380 SUMMARY OF CURRENT RESEARCHES RELATING TO 



(5) the elimination of carbon dioxide. He concludes in favour of the 

 diffusion theory. It is pointed out that the chitiu which forms the 

 cuticle of the gill and the intima (endotrachea) of the capillary tube, is 

 a colloid substance which admits of the passage through it of gases by 

 diffusion, and is particularly partial to carbonic acid gas. Attention is 

 directed to the economical interplay implied in the use of the expulsion 

 of water from the rectum as a means of propulsion and its use in 

 supplying oxygen. 



Japanese Termites.*— Sanji Hozawa has described the Termites of 

 Japan and given beautiful illustrations of the different forms of each 

 species. It is interesting that Kampfer should have given a circum- 

 stantial account of Japanese Termites more than two hundred years ago, 

 while some naturalists and travellers of the nineteenth century have 

 firmly denied the fact of their occurrence. The author finds that there 

 are twelve to fourteen species, and deals with them in a very thorough 

 way. 



Parthenogenesis in a Silk-moth.f — A. Lecaillon finds that oviposition 

 in females of Bomhyx mori which have not been allowed to pair becomes 

 very irregular. Some of the non-fertilized eggs exhibit the change of 

 colour seen in fertilized eggs developing normally. Shaking the eggs 

 did not increase the percentage of those that changed in colour. It is 

 probable that those eggs which change colour are those which exhibit 

 exceptional parthenogenesis. 



Orientation from a Distance in Ants.J — R. Brun continues his 

 experiments on " homing " in ants. The " higher " ants, which are 

 relatively long-sighted, are able to utilize large distant objects as land- 

 marks ; and some of the "lower" ants, which do not see distinctly 

 except at short range, seem able to utilize big objects in some measure. 



The higher ants can complete the hypothenuse of a triangle even 

 from a considerable distance. This is due not to any kina^sthesia (or 

 sense of angles), but to the utilization of a visible distant landmark. 



In the same species there is some measure of local memory. The 

 recognition of " known localities " is probably a function of the topo- 

 chemical sense, while the choice of direction depends especially on visual 

 memory (successive reiteration of differentiated visual landmarks). 



Topochemical data of a more general kind have a certain role as 

 secondary landmarks. Orientation after transport depends on the 

 locaHzation of illumination by the compound eyes, and is not exhibited 

 if the illumination is bipolar. 



Ants cannot associate a complex succession of diverse positions of 

 the median plane of the body. Except within narrow limits there does 

 not seem to be much kinaesthetic sense of attitudes. There is no " static 

 .sense." But ants are sensitive to gravity, and utilize the hints given 

 by the slope of their route. There is no sense or memory of direction as 



* Journ. CoU. Sci. Imp. Univ. Tokyo, xxxv. (1915) pp. 1-161 (4 pis. and 39 figs.), 

 t Comptes Rendus, clxii. (1916), pp. 234-6. 

 X Rev. Suisse Zool., xxiv. (1916) pp. 355-88. 



