40 SUJD'ARY OF CURRENT RESEARCHES RELATING TO 



toad, Bvfo marinus. Oviposition beginning on October 22 continued 

 regularly for about sixteen days ; the females were dead on November 18. 

 The eggs are light brown, ellipsoidal, smooth and shining. The larvae 

 are active, but feign death on being violently disturbed. They await 

 their host with the front pair of legs extended above and in front of their 

 bodies. A total life-cycle takes roughly 153 days. The male thrusts 

 his mouth-parts, with the exception of the palps, into the genital aperture 

 of the female, and 'sets up probing movements enlarging the aperture. 

 The spermatophore from his genital aperture is guided in. The males 

 largely predominate in numbers. There is no doubt that parthenogenesis 

 occurs, probably producing females only. J. A. T. 



Reactions of Whip Scorpions. — Bradley M. Patten {Proc. Amer. 

 Soc. Zool. in Anat. Record, 1919, 15, 346-7). By comparing the 

 changes from the normal reaction induced by elimination of the various 

 photoreceptors — median eyes, lateral eyes, and cutaneous sensitive areas. 

 — their relative effectiveness was estimated at 1 : 1 • 6 : 2 • 2. J. A. T. 



Colour Adaptation in Spiders.— E. Eabaud {Bull. Soc. ZooL 

 France, 1919, 43, 195-7). A study of Ilisumena vatia and Thomisiis 

 onnstvs shows that these two spiders have only yellow chromatophores, 

 that in darkness or on a white ground all lose their yellow colour but 

 keep their red spots (not in chromatophores), that harmonious colouring 

 with particular flowers is a coincidence and of no value. Experiments 

 show that the loss of the yellow colour, which depends on the illumina- 

 tion, is brought about through the eyes. J. A. T. 



*• Crustacea. 



Study of Tanymastix lacunse Gu^rin. — R. T. MiJLLER {Revue 

 Suisse Zool., 1918, 26, 361-408, 4 figs.). This interesting crustacean, 

 reported from Lake Eichener, is a Branchipod and a neighbour of 

 Branchipns. The author discusses its distribution, the conditions of its 

 life, its life-history, and habits. J. A. T. 



Rarity of Sex Intergrades in Cladocera. — Arthur M. Banta 

 {Proc. Amer. Soc. Zool. in Anat. Record, 1919, 15, 355-6). Fifteen 

 sex intergrade strains of Slmocephalus vttuliis were reared for three 

 years (sixty-five generations), but among the thousands of individuals 

 examined no case was observed. Six sex intergrade strains of Daplinia 

 longispina were reared from some thirty-six generations, but among 

 thousands of individuals examined there was only a sparing occurrence 

 of intergrades. It is evidently a rare phenomenon. J. A. T. 



Gynandrcmorph Daphnids. — R. de La Vaulx {Bidl. Soc. Zool. 

 France, 1919, 43, 187-94, 2 figs.). A study has been made of twenty- 

 four gynandromorphs of Daphnia atJcinsoni. In all cases the gonads 

 were normal ovaries ; in three cases the ova were degenerate, and in 

 two of these cases rudiments of vasa deferent were seen. There was 

 great diversity in somatic characters, especially as regards the anten- 



