ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 163 



represented, and a useful diagnostic table is given. The majority of 

 the forms are new, and thirty-seven new species are established. 



Alimentary Canal of Mosquito.*— Millett T. Thompson gives a 

 detailed account of the alimentary canal and associated parts in the 

 larva, pupa, and imago of Gulex, together with comparative notes on 

 Anopheles and other genera. 



Reactions of Caterpillars and Moths.f — Alfred 0. Mayer and 

 Caroline G. Soule have made numerous interesting experiments, e.g. on 

 the larvteof the milk-weed butterfly {Danais pUxippus). The caterpillar 

 is positively heliotropic to the ultra-violet rays, but almost, if not quite, 

 unresponsive to the rays visible to us. It is negatively geotropic. These 

 two reactions serve to maintain it near the upper part of the food-plant. 

 If it came down it might starve before it found another milk-weed. 



The caterpillar has no inherent perception of the form or colour of 

 its food, but is guided by a chemical sense. Once the eating reaction 

 has begun, the caterpillar may be induced to eat substances which it 

 would never have commenced with. This tendency to continue activity 

 " in the face of a non-stimulus," is called the momentum of its reaction. 



If a " distasteful " leaf is presented at intervals of 1| minutes, the . 

 caterpillar takes about the same number of bites each time ; but if it be 

 presented at intervals of about SO seconds, the larva takes fewer and 

 fewer bites, and then ceases. No associative memory of more than 

 1| minutes' duration can be demonstrated in caterpillars. 



A constantly repeated stimulus loses its effect, and this may be due 

 not to fatigue, but to internal changes which express themselves in 

 modified behaviour. 



The caterpillars of Samia cynthki and Callosamia promethea are 

 negatively geotropic when about to pupate, and always pupate head 

 upward, even if the cocoon be inverted when the outer case has been 

 spun. The mating instinct of Porthetria dispar is, on the part of the 

 male, a reaction of chemotaxis. The normal females show a decided 

 selection against wingless males, though not against abnormally coloured 

 ones. The blinded female does not select against wingless males. 



Grdlls due to Larvse of Copium.$ — ^C. Houard describes the peculiar 

 effects produced in the flowers of Teucrium chammdrijs and T. mon- 

 tanum by parasitic larvae of Copium (a genus of Tingida^, Hemiptera- 

 Heteroptera). Thus, to illustrate, the walls of the corolla are thickened, 

 affording nutritive tissue for the larvge ; on the other hand, there is 

 castration of the reproductive organs of the flower. 



Kakao Capsid.§— 0. M. Renter points out that the " bark-bug " of 

 the West African kakao, recently described by Th. Kuhlgatz as Derma- 

 tostagps coiitumax g. et sp. n., is identical with a genus of Bryocorarise 

 described by Hag^lund under the name Sahlbergella, and is closely 

 related to Odoniella Hagl., Rhopalisechaus Rent., and VolJcelius Dist. 



* Proc. Boston Soc. Nat. Hist.,xxxii. (1905) pp. 145-202 (6 pis.). 

 t Journ. Exper. Zool., iii. (1906) pp. 415-33. 

 X Comptes Rendus, cxliii. (1906) pp. 927-9. 

 § Zool. Anzeig., xxxi. (1907) pp. 102-5. 



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