ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 545 



first. During the night or when the sand is cooled, migration from 

 beneath the remains takes place, the larvae travelling 20 ft. or over, and 

 again burrowing. The pupal period is quite regular, though differing 

 with the species. Outlines of the several life-histories are detailed, and a 

 number of facts are given with regard to the normal growth through 

 larval and pupal stages, effects of over- and under-feeding, and other 

 matters, as well as an account of several experiments on various 

 tropisms. . 



Culex fatigans and Dengue Fever.* — P. M. Ashburn and C. F. 

 Craig experimented with CalexfaUgans reared from the &gg, and found 

 that these in one case, after being allowed to bite a dengue patient, sub- 

 sequently communicated the fever to an individual isolated in a mosquito 

 net who had not in any other way been exposed to the disease. The 

 authors failed to find any organism either in the stomach or tissues of 

 infected mosquitos which might be regarded as a stage in the life-cycle 

 of a protozoon. They conclude that the dengue parasite is ultra- 

 microscopic in size. 



Diaposematism in Butterflies.f — F. A. Dixey gives an interesting 

 account of diaposematism or interchange of warning characters between 

 mimic and model in the case of Hiqjhina corva and Txias baliensis from 

 the island of Bali. On the one hand Huphina corva mimics Ixias 

 Ml lens is in the matter of a dark border on the hind-wing, whilst in the 

 fore-wing the Ixias has departed from the usual aspect of its nearest 

 relatives, becoming in this case the mimic while the Huphina stands as 

 the model. 



Cryptic Resemblance in South American Insects.^ — E. B. Poulton 

 describes a moth Dracenta rusina Druce which bears a cryptic resem- 

 blance to a dead leaf partially destroyed by fungi, and a locustid 

 PlagiopUra hicordata from the same region which probably resembles 

 a much bent or even rolled green leaf which has been attacked by a 

 species of fungus. 



Dimorphism of a Geometrid in relation to Mendel's Law.§ — L. B. 



Prout reviews the results of certain extensive heredity experiments with 

 the geometrid Xanthorhoe ferrugata (Clerck) from which he concludes 

 that the colour dimorphism does not obey Mendelian law. If there is 

 any co-relation at all between the colouring and gametic purity, it must 

 be of so involved a nature as to baffle our present powers of discern- 

 ment. 



Physiology of Insect Metamorphosis.||— S. Metalnikoff has inves- 

 tigated this subject experimentally. At the beginning of metamorphosis 

 there appear in the blood of insects definite specific toxins which 

 apparently lead to the poisoning of definite tissues and cells. By this 

 means these fall victims to phagocytosis. It is not improbable that 

 these toxins are strictly specific with reference to the different tissues, 



* Philippine Jouru. Sci., ii. (1907) pp. 93-152. 



t Traus. Entom. Soc. London, 1906, pp. 521-4 (1 pi.). 



% Tom. cit., pp. 533-8 (1 pl.V § Tom. cit., pp. 525-31. 



ii Biol. Ceutralbl , xxvii. (1907) pp. 396-405 (3 figs.). 



