200L0GY AND BOTANY, MICROSCOPY, ETC. 571 



functions. By the action of the muscles of the crop the entrance to the 

 stomach is closed, so as to stop the flow of the contents of the crop to 

 the bell or enlargement ; by the pressure of the transverse musculature 

 of the stomach the contents of the enlargement are emptied into the 

 chyle-intestine, while the return into the crop is prevented. In the 

 Dolichoderidfe and Plagiolepidinae the closure in both cases is effected 

 by the valves. The longitudinal musculature is only found in such 

 stomachs as are not elongated or too compressed ; in many of the 

 DolichoderidjB the stomach is very short, and there is no longitudinal 

 musculature at all. 



The primitive type, from which the various forms of stomach have 

 been evolved, may be imagined to have been an elastic chitinous tube, 

 provided with four longitudinal folds, and surrounded by longitudinal 

 and transverse muscles ; the primitive function was probably the peri- 

 staltic contraction of this musculature, by means of which an incomplete 

 pumping action -was effected. The genus Doliclioderus is a very lowly 

 differentiated form, but a more indifferent stage is found in the Poneridaa 

 and Myrmicidfe, where the crop is continued backwards into a cylin- 

 drical or conical tube, from which the longitudinal muscles appear to be 

 wanting. 



The author gives a phylogenetic table, in which is exhibited his view 

 of the relationship of the genera he has examined. 



Senses of Ants.* — M. Aug. Forel, in an appendix to his former 

 memoir, first corrects an error in regard to the absorption of the ultra- 

 violet rays, and then cites two recent works which coniirm the con^ 

 elusions previously arrived at by him. 



Mr. G. W. Peckham affirms, after numerous experiments, that wasps 

 do not hear, but that they have memory and a sense of smell, and that 

 they possess no such mysterious instinct of direction as is indicated in 

 the terms "bee-line" and "wasp-line." If they are far away, they 

 can only find their nests by seeking for them. Handl maintains, with 

 Forel and in opposition to Graber, that animals do not perceive colours 

 by their skin. 



Finally, M. Forel gives an account of a series of experiments made 

 by him upon ants. These have led him slightly to modify his former 

 opinion, and to conclude that, though, in general, they use both senses, and 

 are entirely lost without their antennae, without eyes they may s-ucceed 

 in finding their way back to their nest if the task be not too difficult. 



Parthenogenesis in Bombyx mori.j — Signer E. Verson draws atten- 

 tion to a suggestion \ that' it might be possible to produce the silkworm 

 parthenogenetically. He points out that this parthenogenetic develop- 

 ment does not go further than the formation of the serous membrane. 

 After an experience of twenty years he feels confident that no real 

 parthenogenesis can obtain in the silkworm. 



Karyokinesis in Lepidoptera.§ — Herr G. Platner has studied karyo- 

 kinesis in the spermatocytes of some Lepidoptera, and bases on it a 

 theory of cell-division. The author believes that the separation of the 



* Eec. Zool. Suisse, iv. (1888) pp. 515-23. 

 t Zool. Anzeig., xi. (1888) pp. 263-4. 



j By Prof. Krause in the ' Jahresber. iiber die Leistungen u. Fortsehritte in. der 

 Ges. Medicin.' 



§ Internat, Mouatschrift f. Auat. ii. Hist., iii. pp. 341-98 (2 pis.). 



