Chromosomes and Genes

I have been asked to report here upon my present views on the problem of “Chromosomes and Genes.” I emphasize the words “present views” and explain the reason for this by the quotation of an autobiographical remark by Darwin: “I have steadily endeavoured to keep my mind free so as to give up any hypothesis, however much beloved, (and I can not resist forming one on every subject) as soon as facts are shown to be opposed to it.”