ZOOLOGY AND BOTANY, MICKOSCOPY. ETC. 319 



To each total 10,000 may be added for those not captured. Even 

 then it will be seen that most are under 100,000, that there is consider- 

 able variety, and that there is a proportion between size of nest and 

 number of inhabitants. Yung thinks that both Forel and Lubbock have 

 exaggerated the numbers. 



Ants in Artificial Nests. * — Prof. H. Keichenbach has been very 

 successful in keeping ants in nests made of plaster of Paris and con- 

 taining chambers covered with small mirrors. In such nests he has kept 

 many species, and has made a variety of observations on their habits. 

 In regard to the psychical activities of the ants, the author is inclined to 

 agree with Forel that these depend primarily upon inherited automa- 

 tically acting instincts, but he does not deny the ants the power of pro- 

 fiting by experience to some extent. 



Choice of Colours by Insects.')" — After a review of the recent litera- 

 ture on this subject, Prof. F. Plateau gives an account of further ex- 

 periments which confirm his previous conclusion that colour is not the 

 primary factor in attracting insects to flowers. Although flowers are 

 undoubtedly seen by insects from a distance, either from their colour 

 or from some other contrast with their surroundings ; when they once 

 reach the flowers, it is perfectly indifferent to them what their colour 

 may be — blue, red, yellow, green, or white — if they differ from one 

 another in no other respect. 



Vision of Anthidium manicatum L.J — Prof. F. Plateau has made 

 observations on the visual power of this bee, one of the Megachilidge. 

 Superficial observations suggest that it has excellent sight and can dis- 

 tinguish the form of stationary objects with precision ; but more careful 

 observation of the way in which the females behave to flowers leads to 

 a modification of this conclusion. Similarly, as to the male, he passes 

 close by the female when she is resting and fails to detect her presence ; 

 even when she flies he sometimes fails to distinguish between her and 

 other species. 



Hexagonal Structure of Beeswax.§ — Mr. F. Chapman points out 

 that crystalline structure in the wax has no effect in producing the 

 hexagonal markings seen on the surface of cooling wax, as suggested by 

 Messrs. Dawson and Woodhead. Indeed, the more nearly homogeneous 

 a substance is, the more readily are the hexagons produced. Mr. Chap- 

 man doubts whether the phenomenon — which produces the characteristic 

 jointing of igneous rocks — can be compared with the natural cells of 

 honeycomb, for the melting-point of beeswax is too high for it to be 

 supposed that the bees can melt the wax. 



Development of Drones.|| — Herr W. Paulcke found, in 8 out of 12 

 eggs taken from workers' cells about a quarter of an hour after they had 

 been laid, that the sperm-nucleus and its radiate system could be observed. 

 But in 800 eggs from drone-cells no spermatozoon could be detected. 

 Thrice he saw little dark corpuscles which might possibly be sperm- 



* Ber. Senckenberg. Naturf. Ges., 1899, pp. 95-6. 



t Mem. Soc. Zoal. France, xii. (1S99) pp. 336-70. Cf. this Journal, 1899, p. 29S. 



X Ann. Sou. Ent. Belg., xliii. (1899) pp. 452-6. 



§ Ann. Nat. Hist., v. (1900) p. 320. Cf. this Journal, ante, p. 19S. 



H Anat. Anzeig., xvi. (1899) pp. 474-6 (2 figs.). 



