Crew, F. A. E.

2018-09-13T16:06:17Z

2018-09-13T16:06:17Z

1921

The problem of sex -determination possesses a peculiar fascination for the student of. animate Nature and the fact that it remains as yet unsolved, permits one to set out on the great adventure of its solution with high hopes and, if one is young, with confidence.

But with the experience of the difficulties and complexities of the subject comes a chastened mind, and at the journey's end one is left with just the hope that in the results of the work which has enslaved by its all -absorbing fascination, there may be found some suggestion as to the direction in which the truth of the matter really lies.

In this study the question of sex- determination is approached through a consideration of the abnormalities of the reproductive system which have been recorded in Zoological literature. Often an appreciation of the abnormal can illumine the mechanism of the normal.

The typical sexual characters are first briefly described, so as to furnish standards to which the abnormalities may be referred. The abnormalities are then tabulated and analysed. A brief consideration of the embryology of the reproductive system naturally follows and the investigation is brought to a close by a review of what is known of the sex-ratio. An account is given of certain experiments.

It is intended to demonstrate that the abnormalities obviously suggest that in the case of the frog, sex is not irreversible; that the facts of embryology lend support to this view; and that a .study of the variations of the sex -ratio supplies conclusive proof that sax- reversal can and does occur. The graduated degrees of abnormality as portrayed, are shown . to provide a clear view of the process by which sex-reversal is effected.

http://hdl.handle.net/1842/32697

The University of Edinburgh

Annexe Thesis Digitisation Project 2018 Block 20

A contribution to the study of sex-determination in the anura

Thesis or Dissertation

Doctoral

DSc Doctor of Science