Experiments on Plant Hybrids by Gregor Mendel

Here, translated into English, GENETICS republishes the original Mendel article. As discussed in the Perspectives by Daniel J. Fairbanks and Scott Abbott this translation differs from others in an attempt to be both more accurate than previous translations and also more accessible. GENETICS wishes to thank Scott Abbott and Daniel J. Fairbanks for their labors in presenting the scientific community with this new translation. Artificial fertilisations of ornamental plants to produce new colour variants led to the experiments discussed here. The striking regularity with which the same hybrid forms reappeared whenever fertilisation took place between the same species was the stimulus for further experiments, whose objective was to follow the development of hybrids in their progeny. Careful observers like Kölreuter, Gärtner, Herbert, Lecocq, Wichura, and others have tirelessly devoted parts of their lives to this objective. Gärtner especially, in his work “The Production of Hybrids in the Plant Kingdom,” documented very worthwhile observations, and most recently, Wichura published fundamental researches on willow hybrids. That a generally standard law for the formation and development of hybrids has not yet been successfully given is no wonder to anyone who knows the extent of the subject and who realises the difficulties with which experiments of this kind must struggle. A final determination will result only when detailed experiments on the most diverse plant families are available. Anyone who surveys the work in this area will be convinced that among the numerous experiments, none have been carried out in the extent and manner that would make it possible to determine the number of the various forms in which the progeny of hybrids appear, so that one could, with confidence, arrange these forms into the individual generations and determine their relative numerical relationships. Some courage is certainly required to undertake such an extensive work; nevertheless, it seems to be the only proper means to finally reach resolution of a question regarding the evolutionary history of organic forms, the importance of which must not be underestimated. The present treatise discusses an attempt at such a detailed experiment. It was, the to a of plants and was only the of the by which the individual experiments and carried out to the given objective be a The and of are by the of the by their this it be which plant species are for the the manner in which it is The of the of plants for experiments of this kind must be with the one not to the in question from the The plants must the of their hybrids must be from the of from be The hybrids and their progeny in the generations must not in from such to in the of the would to of individual forms, like that in the progeny of would the experiments the of the hybrid forms to one and to their original it to be that that in the in be to the was given to the of their with of this led to the that the the forms of this that are and certainly and to hybrid progeny when by from not the of are by the and the in the so that the is by the is of that are the of these plants in and in their Artificial fertilisation no it is this the not yet is the and with the be with from A of more from and to a one a forms among a number of The was no among and from the same in the been the and at in the no was for and the of the to The is and one to the of the to which only that the same the same to the same no be a to the of in the the to the species the others and of such and these are for the experiments here. It is to a of between species and it is to a fundamental between the hybrids of species and plants that are in one more are the in are to the hybrids and their numerous experiments have of in the hybrid to a new that generally is subject to in the progeny. these for of and to a law to which in generations was the objective of the experiment. into individual experiments are in the The forms for fertilisation in the and colour of the in the and of the in the and of the in the of the in the and of the in the and of the and in the colour of the and of the Some of these not and the on a that is to not be for the individual experiments, which to be to that and in the A result would finally are in hybrid and a a is possible that are in their The in the experiments The in the of the are and the on the and are only are and The in the colour of the The of the is it a more in colour is to in the their are The in the colour of the is a with it is with in which the colour of the standard that of the and the at the of the is The in The in the of the is in between the and more The in the colour of the It is to a a colour by and The in the of the are the at the of the in a in which the of the is more in The in the of the The of the is very in individual for one it is a the plants are and are in the same the experiments with this to a the of was with the one of of the to the a number of plants of the same only the most for in the of the and more so in the of the not in produce only and in experiments in this of the that plants for a number of fertilisations was the plant for the The plants in a number of in and in the by means of and a number of plants in a the a for the in of possible by that the the species be for the it in The of this species is to in the and in so the on the of one in a a must be in that to the of from individual parts of the which a of the of development of the was in which the and It also that the not this a of the the from the of the has been in hybrids of and The of by from individual is very for and in no the result a more than the of such only a no such was in the it be that and the to in the are to The experiments with ornamental plants in that a not the between the original individual that are like to the and of the and to the of the individual the is in in one of the original such an that it is to the in the is the of the hybrids. of the hybrid one of the original so that the one is so like it that a be is of importance for the determination and of the forms among the progeny of the hybrids. the that are in the hybrid that the hybrid are and that in the are The was the in the among the progeny is it has been the experiments that it is the to the plant to the the hybrid the same in both to Gärtner, with the that the most is not to in a hybrid which of the species was the the the into the experiments, the are the with the colour of the the colour of the in with and in the the of the the colour of the with the same colour in the and the of the the and the of the to this it must be that the of the is generally by that of the which be to the that in parts of the plant when of very are in the for in experiments of and of in hybrid whose between and hybrids the is more and the into The when it is in the original The hybrid forms of the and fertilisation the of the from be the of the others only in the in the plants from the this with the the in their and so in the and of so that of plants from this produce the and one the for in the experiment. The of the the colour of the the colour of the and of the the of the the colour of the and of the and the and the in these to numerical forms in none of the the hybrids from a and no in their further the for be The for of are of the in the these and The is of the A of plants and the to the in the these experiments one generally both of in that on it was the that of the more than in one It not to make the on the hybrid it to the to a a plants only in the and these one of the in the that the As in the individual the of among individual The from both an As in the of the in one in the and only and in and the and only also in and experiments are for the produce with a number of the in the is required in of plants the colour of the is and at be The of the of the colour has no to the hybrid of the that in the original plant in this is only to the individual and is not by the progeny. has been in by their development in colour and with in are It is to that the must on the plant have and have only are the and the colour of the of the and and in a of of the and the is of the The number of plants was of which and the of the to the is of the the the and is of the and this relative is this the plants and to was would have among their their are by their and their the of experiments are is an between the number of forms with and of The have a that of the original that of the hybrid of these in be only in the original must be to the hybrid must follow the same in the forms that the in the not in the in to that in their progeny. is not the for that the in the these progeny that the and in the and the same the hybrid only with the The individual experiments the plants from of the only and in this and in the the number of hybrid relative to the number of is plants from whose in the the and in the in of hybrid and forms in the of the experiments, plants that the in the and to from The progeny of plants from plants with and with The progeny of plants only of and The progeny of plants only from of plants and The progeny of plants only the of the and experiment. The progeny of plants from plants and of these experiments a number of plants with the is determination of the in which place for the forms with the the experiments are of importance a number of plants be The and result in the The has an in the others the more must be given the number of The which the was and of the the The it is that of the in the the hybrid with the The which in the of the and in the for experiments into the one the in a hybrid and an original the of the from the of the it that the hybrids from of of which the hybrid the plants that and produce in parts the and the The to which the of the hybrids and in the and generations are in for The and experiments have been the and and the and from the with a number of The progeny of the hybrids in into hybrid and forms to the The by Gärtner, Kölreuter, and others that hybrids the to to the original species are by the experiments It be that the number of hybrids from fertilisation from to when to the number of forms and their progeny that have one that on plants in generations have and one further that hybrid forms of which the with both in the for the progeny in be by the A and a the original and the hybrid the of that plant in forms only the for are plants that from this are that are for the with the and only hybrids. the experiments plants that in only one The objective of the law for of was when are in the hybrid As for the of the hybrids in this the experiments in that the hybrid more the original plant that the number of for the plant has a and the plant has a the and the hybrid the plant only in the of the in the it is to the one of the original only the hybrid is not at from experiments carried out with a number of the the original plants in the of the and in the colour of the and in the in the of the the colour of the and the colour of the with to the and most an of these experiments, the of the plant are with and of the plant with and and the hybrid forms of these with and The from fertilisation and of the The plants from of that in one from of these and and and and and of the the not produce plants and plants not produce the and and and and and the plants of which only and and from which with only and with and The plants with this same of The progeny of the hybrids in forms and in The is the result when these are and of the forms be into The one with the only and no more in of these forms is on The the forms these are in one hybrid in the and in the only for the hybrid of on The is hybrid for both and like the hybrid from which it is one the number of forms that in of these the are The are very of the was in a manner to the previous the experiments it required the most and A of from of which and plants the further researches among the The are for and on are for hybrid for the on are for one hybrid for the of on and one and is hybrid for The so to the that the the The development of the when their original are in to the various experiments with a number of plants in which the of the in and in the the same no that for of the into the experiments the is The progeny of hybrids in which are the of a in which the for of are it is that the of of in hybrid is of between the original the number of the in the original the number of in the the number of that to the and the number of that for the original have the and in among progeny from hybrids are of which are that are possible in the to number is given is that in forms of a plant in possible to the of on the of the hybrids are not yet It is possible to in that that place at a between that of the and the and the development of the hybrids in to this will follow in the same manner for the The forms for experiments of this kind must in the by at it is that the when are at the same in the to produce and in the must be into to the of this has difficulties that must be to the that for that and of the in hybrid of the progeny of the hybrids for of is also the is in for the of the and are in one hybrid the progeny the of a in which the for of are The by in the and the that the same to that in the plants and not be in the individual with of on the a and of the forms not be with the same that is for The of the experiments led to further experiments whose of on the of the and of the hybrids. of is in by the that forms in the progeny of hybrids and so in of the it to be that progeny be only when the and the are the in that both are with the to is the with fertilisation of must it that the very same in the of forms in the hybrid the forms are in one in one of the it to that in the of the hybrids and in the are possible forms and that these and to the individual forms in their it be that this would be to for the development of the hybrids in individual one to that the of and on in in the these the experiments forms that in the of the and in the colour of the the are one has The with of the original and the most for The fertilisations the hybrid with the of the hybrid with the of with the of the and with the of the of these experiments, the of plants the is the and must forms in the hybrid and be the with the the with the the with the and the with the of these experiments, only the forms and the individual forms of the and of the hybrid on in in the would be in their numerical relationships. A of the numerical was not in individual and of the not in this is in that the formation of the and in and not that individual hybrid such with The and experiments the of the of the hybrid and the and experiments of that of the As the the and experiments, and the and produce the same to these be the in the and colour of the the and experiments, the of and A and in one in and the in hybrid with the a and and of this must their of the the must this is and the and experiments, one is hybrid in and colour and the are and is hybrid in and in the of colour and the are and the is in the of and hybrid in colour and the are and and the is in both and the are and these experiments, and The to these in the in the in the and and in the and was no a the would produce the final the in the plants in the and in the in the the and experiments the and plants with and and the plants with and The plants with and the plants that only not in these experiments, the in the previous not be by that kind of plants in to their among and from the from the of the experiments, forms this required in in the same the of colour and into the experiments and the so that in the would in of plants the for the and The was with the hybrid was also with the hybrid the the hybrid was the plant for further fertilisation and the hybrid the possible and fertilisations in the from which plants in in the the individual in the the colour in the colour in the in and the in The in this the of the and experiments and possible the of and in means the is that hybrids and to their in to the forms that from the of The forms among the progeny of the the numerical in which are a in the The is by the for of It is that this is by the A in which A and a the forms with and the hybrid of It among the their and of the forms A and a in on in and are in fertilisation are the A A a and the A A a It is a of which of the of with individual to the of in the of A and a with a A and one of the A will with a A the fertilisation and the with a in the same one a will with a A and the with The result of fertilisations be the for and are with the the the in this the and the and are the so the of their must be A and the and a of the original and the forms that from this fertilisation are to the hybrid from which are a for the striking that the hybrids are like the original forms, to produce progeny that are to and both produce the same to it no for the result of fertilisation which of the to the is the for the of hybrids when are in individual and in individual the which of the are that are not for the that the of both of in the be only on to it to which of the of individual the individual and are possible to in the experiments on and the colour of the The numerical be only the from the of the possible number of individual the their number the more are The development for hybrids in which of are forms with the of the original plants a and are and the hybrid the forms of and and of on into fertilisation are in the in fertilisation are the and the The for hybrids be for in a manner when of are The hybrid forms of and and on with The law of of the by which the development of hybrids and in the that hybrids produce and in number to forms that from the of the The objective for further experiments will be to the law for is also for hybrids of this experiments experiments with species of have been and here. with and a with a a to and that at the of The numerical in which the forms in the individual generations the same in The development of also to the law of of is the in The of the and the in with very species only the plant was a very species with on and in and and the plant was with a on very and that are and on a The hybrid was most to the only the was very plants that of a of only of and the colour was not the plants of which only in of that in the hybrid reappeared in their of the number of with individual such and the the was in As the result of this be for the numerical in which the forms it on the a of a of colour in the and of the hybrids. As is to in the of colour and colour in the and and the progeny of hybrids one the of the original is not the in this experiment. The and colour of the same in one in the the plants that of to The colour of the was no from that of the plant be no at and with others the only from the and from only The was in the forms with in which only from of with a more and the plant only a with a The forms with and The was generations among the progeny of plants and than the not The forms that one more of the in the for plants that and no in and colour in the the in to with and The plants so that in be their further the difficulties these to this at that the development of hybrids the same law in in to to the of the to the colour it seems to the that a of from the of a a and from to and it is a striking that of plants that only one the of with such is the for plant on these be to the that are for one that the and colour of are a of more that like of a colour A of the that the of fertilisation with the of colour a the hybrid would be and would be with the colour of the to the of these hybrid colour would be and would from the by the individual a colour must for A the hybrids and would to the The of these in and of the for The for the individual plants with the colour to the that on are to of the in the development of took place in this the be and colour only among plants of the colour is only in the and on for plants with colour only for It must not be that the is only on a that has no than the very result of the It of be a worthwhile to follow the development of colour in hybrids with experiments, it is that in this would to the of in ornamental this more is with than colour in most ornamental plants is an The has been that the of a species has been to a is a to to the development of forms and by the colour of ornamental plants is generally a of It is not the in result in such a and in the plant one will that the development of plants in a is by than in a Here, must the of are for a and it has the to to the new It is the of new is and by the of a is that would have in the the to that the for new to is so that species and that their into an of the in the of the of one would be in that plants the same for would have As is this is not the for among not only the most also the most forms are the like whose of are by a an for numerous have for more than the most the same of to that of species in the It more than that is a in for the of which has to the that ornamental with are of hybrid whose further development is and numerous The must not be that plants are in to one which the most for fertilisation between the and between species The of this is by the that among the of forms, are that in the one the is forms the same of the hybrid with the most of that of it that with individual forms the in very plants that from one are whose progeny in the and of others produce forms with and when a number is are that colour to their progeny. The species of a A of which from a was in a the the numerous from it plants with the same A result was with a with a that in the same manner progeny with more and surveys the in ornamental plants that from fertilisations the that development place to a law that be the of colour It not be to the on with the of by the in this and to their hybrids in the that is between the original to the of the one the from fertilisation is the are of forms that are from the As a the of the from one fertilisation the hybrid a others more to the plant and one individual to be to the this not to hybrids the progeny more in and in the more to one the to the hybrid and The hybrids of like the hybrids of in and a more to to the original to the of the hybrids and their the with in is It is for Gärtner that the accurate determination of a is more to one the of the is it on the of the could, be that have to and in of the most and for the most are species and that are in a number of for the in with of in to that are that are to in must also be into plant are to the forms a that the development of hybrids place to the to the of must very forms, it is that the number of by of relative to the number of a number of the result be only and in individual not for the original in and plants from the of their hybrids to the of among the the must for the of forms that be on which forms by in into the of the that are to the among that of the original the one that the number of will be more among the of the the experiments with to for the to the the of the in their both original plants in this the plant such that of plants of the of it from it in only one the one it be to the of hybrids from Gärtner that in development was it was not the original that among the progeny of the hybrids only to very extensive it in for among more than progeny of the the original