36 SUMMARY OF CURRENT RESEARCHES RELATING TO 



equal illumination. But the stimulating efficiency depends on the flash- 

 frequency ; it may be greater, equal to, or less than that of continuous 

 light. J. A. T. 



Australian Ants of Genus Onychomyrmex. — W. M. Wheeler 

 {BuU. Mus. Comp. Zool. Harvard, 1916, 60, 45-54, 2 pis.). From among 

 several recent studies of ants by Prof. Wheeler '^e select his account of 

 three species of this interesting genus. A study of the worker reveals a 

 number of highly-specialized characters. Such are particularly the shape 

 of the mandibles, the vestigial condition of the palpi, the small size of 

 the eyes, and the enlargement of the terminal joint, claws, and pulvilli 

 of the middle and hind tarsi. The powerful, toothed mandibles, long 

 sting, and great hooked claws indicate that their possessors do not feed 

 habitually on small feeble insects like Termites, but on much larger 

 creatures such as the larvae of Passalids and Scarabteids, and possibly on 

 adult Myriopods and scorpions. An attack on a huge lamellicoru beetle- 

 larva more than 2 inches long was seen. It is not improbable that the 

 colonies move from place to place in search of their prey, like the colonies 

 of the subterranean Dorylina3 {Eciton ca-ciim and Dorylus), which they 

 very closely resemble in behaviour, colour, sculpturing, and pilosity. 



J. A. T. 



Hibernation of Flies. — G. S. Graham-Smith {Parasitology, 1918, 

 11, 81-2). An old house in Lincolnshire showed enormous numbers 

 of " hibernating " flies. " After fumigation a bucketful of flies was 

 removed from a single window-frame, and about six bucketfuls from 

 other infested windows." This is said to have recurred every winter for 

 twenty-four years. The most abundant fly was Miisca corvina, but there 

 were four others. There were numerous specimens of the Chaleid 

 Stenomalus muscarum. The " hibernating " flies shifted their quarters 

 from time to time and returned again. " They might be present in 

 hundreds on one day and have disappeared on the next." J. A. T. 



Gynandromorphism in Drosophila. — T. H. Morgan {Proc. Amer. 

 Soc. Zool. in Anat. Record, 1919, 15, 357). Gynandromorphs appeared 

 in the ratio of 1 to 2200. There is evidence that nearly all start as 

 females. Practically all the cases appear to be due to the elimination of 

 one sex-chromosome soon after fertilization, but a few cases require the 

 assumption of- a bi-nucleated ovum. J. A. T. 



Chromosome Dislocation. — C. B. Bridges {Proc. Amer. Soc. Zool. 

 in Anat. Record, 1919, 15, 357). In Drosophila melanogaster several 

 cases of abnormal inheritance are accounted for by the assumption that 

 in each case a piece of chromosome (the locus of a particular factor) has 

 been taken from its normal position and joined to another chromosome. 



J. A. T. 



Bionomics of Tsetse Flies. — J. J. Simpson {Bull. Entomol. Research, 

 1918, 8, 193-214). There are no defined "fly-belts." A forest fire 

 only disturbs the tsetse for a short time ; the pupae are not destroyed. 

 The different species of Glossina frequent different types of vegetation, 

 which are discussed. Besides mammalian blood, the tsetse flies may 



