198 SUMMARY OF CURRENT RESEARCHES RELATING TO 



on the relation of the colour of the pupae to that of the surroundings of 

 the larvae before pupation in various Lepidoptera. In the case of Papilia 

 machaon the result is to show distinct susceptibility to the colour of the 

 surroundings. In Pieris napi not only is there a high degree of sensi- 

 tiveness but also a very wide range of controllable modification. A very 

 extensive series of experiments were made on P. brassicse, the result 

 being to amplify and confirm the previous observations. Experiments 

 with this species when placed on a particoloured background tended to 

 show that under such conditions pupas of uniform intermediate colour 

 are obtained, not parti-coloured ones. 



Food of Ants.*— Prof. C. Emery has experimented on the food-sub- 

 stances which can be utilised by Messor structor, a graminivorous species 

 common in Italy. The ants consumed fungi and mycelia of various 

 kinds supplied to them, and also mould growing in the plaster of the 

 artificial nest. They also ate unripe grains, buds, dry cooked beef, 

 grains of rice and other cereals, bread and raw Italian paste, but rejected 

 raw starch. On an exclusive diet of Italian paste, the ants were able to 

 rear their larvas, which the author regards as proof that the saliva con- 

 tains a peptonising ferment. 



Hexagonal Structure in Cooling Beeswax.f — Messrs. Charles 

 Dawson and S. A. Woodhead find that if a thin slab of beeswax be 

 melted in a tray, and allowed to cool gradually in a warm atmosphere, 

 hexagonal forms of the ordinary size of the cells of the hive-bee gradu- 

 ally appear in the wax. The process appears to be crystalline or pseudo- 

 crystalline, and the authors believe that it explains, at least in part, the 

 structure of honeycomb. When such plates of wax are supplied to the 

 bees, they utilise the natural " cells," hollowing them out, building up 

 their walls, &c. The particular crystalline form seems to be character- 

 istic of beeswax. 



/3. Myriopoda- 



Male Dimorphism in Diplopoda.J— Dr. C. W. Verhoeff distinguishes 

 what he calls morphologische Doppelmannchen (in some Amphipods and 

 Arachnids) where dimorphic males, similar in development, are dis- 

 tinguished by some sexual characteristic, and genetlsche Doppelmann- 

 chen in Diplopoda (Tachypodoiulus albipes, lulus nitidus) where small 

 and large males occur, the latter having in their development one stage 

 more (Schaltstadium) than the former. In maturity the two forms do not 

 differ in special characters, but in size and number of segments and 

 appendages. Moreover, the small males seem to be protandric, and the 

 large males hysterandric. 



New and little-known Lithobiidse.§— Dr. Carl Verhoeff, in pursuing 

 his studies in Palaearctic Myriopods, describes some new species of the 

 genus Lithobius, some of which were found in caves. In the course of 



his descriptions he notes that one of these— L. matulicii, a blind form is 



of simple organisation, and must have been blind before it reached a 

 subterranean habitat ; while another form, L. leostygis, though of higher 



* Arch. Sci. Phys. et Nat, viii. (1899) pp. 488-90. 



t Ann. Nat. Hist., v. (1900) pp. 121-6 (3 figs.). 



X Zool. Anzeig., xxiii. (1900) pp. 33-46 (2 figs.). 



§ Vein. Zool.-bot. Ges. Wien, xlix. (1899) pp. 446-59 (7 figs.). 



