704 SUMMARY OF CURRENT RESEARCHES RELATING TO 



If the genital tract contains " determinates " which are dominant 

 and recessive, it follows that it is an impure dominant, and that the 

 zygote, containing causal dominant and recessive determinants, is an 

 impure dominant of F 1 . For reasons we cannot detail, the dominant 

 and recessive genital determinants are considered as coupled — e.g. in 

 the human species, behaving as one autonomous character. The segrega- 

 tion of these does not take place normally or abnormally in the human 

 species — i.e. does not pass on to the segregation shown in peas in F 2 . 

 The question is next discussed as to the origin of the gametes (ovum, 

 spermatozoon). The usual view of their origin from the' germ or 

 sperm-epithelium of the sexual gland is rejected, and they are considered 

 as originating in the earliest division of the zygote, a view we owe to 

 Owen (1H49), and especially to Eigenmann, Boveri, Beard, and many 

 other observers. This view of the continuity of the germ-cells is 

 elaborated and termed the Owen-Weismann law for convenience, and in 

 recognition of its two principal discoverers. 



The zygote is due to the union and blending of the gametes, and 

 the question arises as to how many gametes are necessary. The main 

 views are : (1) male and female eggs and a male gamete ; ("2) single 

 male and female gametes ; (3) a sex male gamete and a non-sex male 

 gamete with a sex female gamete and a non-sex female gamete. The 

 second view is the usual (me. The theory, however, that the human 

 zygote is an impure dominant owing to the presence of the non-potent 

 determinants makes it less feasible, and the author advocates the third 

 view. 



The zygote necessarily contains the determinants for the complete 

 organism, and the gametes, combined, contain them too. The male 

 zygote is supposed to result from the union of a sex spermatozoon and a 

 non-sex ovum ; the female zygote from the union of a sex-ovum and 

 a non-sex spermatozoon. This will give the practical equality of the 

 sexes. 



Have we any means of allotting the unit characters to the gametes ? 

 Attention is drawn to such a source. In men, and especially in women, 

 what are termed dermoid tumours are found, almost always in the ovary 

 and testes. When these are solid they are termed teratomata, or 

 embryomata, and consist of elements of all the germ layers, and practi- 

 cally may form the anterior part of an embryo. 



Shattock has published an account of a specimen of ovarian 

 embryoma now in the Museum of the College of Surgeons, London, 

 which has a spinal column, limbs, peritoneal cavity, with a small coil of 

 intestine and labia majora. The tissues are normal in teratomata. 



In no specimen has evidence of the presence of genital organs been 

 found (testes or ovary). Okhubo has published a full account of the 

 known testicular teratomata, and confirms the structural facts as to 

 ovarian dermoids. Many views as to the origin of embryomata have 

 been advanced ; the author adds to them by suggesting that they arise 

 from a non-sex gamete which has retained the power of zygotic develop- 

 ment, lost when the primitive germ-cells are reduced to gametes. He 

 thus considers that the early zygote first divides into a propagative part 

 and a somatic part ; the latter forms the individual. The propagative 



