Observations upon the Growth of Young Chickens under Laboratory Conditions

There are not many published records of the use of young chickens as the experimental animals in studies upon the factors concerned in growth and nutrition, but, from a reference to those of recent date, the present author was led to believe that one might rely to some considerable extent upon their suitability for such studies.When the present work was begun, it was intended to make a full study of the effect of various diets upon tumour growth in the young, growing chick.The particular tumour which was selected for use was one of the aviani neoplasms desclibed by Rous [1910].This growth, originally found by him in a Plymouth-rock hen, simulates in manv respects a spindle-celled sarcoma.It is very suitable for the study of the effect of diet upon tumour growth, on account of its high degree of virulence, its rapid growth, and its great tendency to form metastatic deposits in other parts of the body.Peculiar interest is also attached to the growth from the fact that it may be transmitted by means of the cell free filtrate from the crushed tumour.For this reason, as well as on other grounds, many workers consider that the growth should be classified as one of the inifective granulomata, rather than as one of the true sarcomata.Whether this is so or not, is a matter which remains as yet undecided.Meanwhile it was felt that the tumour sufficiently simulated a true sarcoma to warrant an investigation along the lines previously mentioned.At the outset of the work, Dr A. Paine, the Director of the Research Institute, brought to my notice an observation that