ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 705 



part (primitive germ-cell mass) becomes the primitive germ-cells, and 

 these are equivalent to zygotes. Normally, they are reduced to gametes, 

 which cannot form a complete organism, but when suitably combined, 

 as in fertilization, get the full tale of determinants a zygote needs. If a 

 non-sex ovum or spermatozoon can form such a teratoma as Shattock's 

 case, then we may consider that the non-sex gamete is somato-pleuric 

 in the main, while the sex one has splanchnopleure and sex deter- 

 minants. This fits in with the popular belief that in the main, the 

 mental and bodily development is derived in girls from the father, the 

 sex from the mother. Boys, on the other hand, take sex from the 

 father, and bodily and mental development in the main from the mother. 

 There is, however, an interchange of paternal and maternal characters 

 hi each case to a certain extent. 



The author urges that there is evidence of Mendelian action in sex 

 development. Mendelism does not differentiate sex, but the sex deter- 

 minants are coupled and present in the sex gamete, and act as Mendelian 

 unit characters. The segregation of the dominant and recessive sex 

 determinants takes place in certain twins of black cattle, where the 

 Free-martin, born with a potent bull, is really a sterile male, with the 

 non-potent parts of the male genital tract segregated in it. The Free- 

 martin is, therefore, an extracted recessive qua its genital determinates, 

 the potent twin an extracted dominant. This has happened from 

 changes in the early zygote, and for this and other reasons the author 

 denies the validity of the theory of the segregation ratio arising by 

 combinations of the gametes. 



He places the human zygote in F 1 of Mendel's scheme, the potent 

 twin as D in F 2 , and the Free-martin as B in F 2 . He promises further 

 proof on this point. 



Development of the Alpine Salamander.* — H. Wunderer gives an 

 account of researches in regard to the biology and development of the 

 Alpine salamander {Salamander atra Laur.). The chief points discussed 

 are, the time of reproduction, the duration of gestation, anomalies of 

 reproduction, the embryonal ova and the nutritive ova, and the phylo- 

 genetic position of the form. His main conclusions are as follows : The 

 uterus of S. atra is only developed as gestation proceeds, by the muscular 

 pressure of the nutritive eggs against the caudal section of the tube-like 

 oviduct, which thus becomes distended. Very early segmentation-stages 

 are never found in a fully developed uterus. The Alpine salamander 

 has a limited reproductive period, which at about 1000 metres above sea- 

 level lasts from the beginning of June to the end of July. The repro- 

 ductive period begins later with increasing altitude, thus at 1700 metres 

 it falls at the end of June or the beginning of July. The greatest 

 production of embryos takes place about the middle of the reproductive 

 period. Under natural conditions at median altitudes the embryos of 

 S. atra go through what Schwalbe describes as the first stage of develop- 

 ment in six or seven weeks. Towards the end of the first year they 

 reach the middle of the second stage, and complete it in .June or the 

 beginning of July of the second year. Birth takes place in the spring 



* Zool. Jahrb., xxviii. (1909) pp. 23-78 (2 figs.). 



