856 Pomona College Journal op Entomology 



rudimentary structures, as authors have called them. They are the organs 

 which serve the orentation of these animals as they crawl under water. 



These structures of the adult are preceded by eight sensory pits of the 

 larva which serve a similar purpose. The pits are abundantly supplied with 

 nerve fibers and trachea and may be surrounded and often covered with 

 sensory hairs. At the regions of the depression there are numerous little pores 

 leading down through the chitin. 



W. 11. 



UBER DIE CHORDOTONALORGANE IN DER WURZEL DER 

 SCHMETTERLINGSFUGEL 



RICH.\RD VOGEL 



Zeit. Wiss. Zool. C. Band, H. 2, 1912. 



This article is concerned chiefly with the structure of these organs in the 

 fore and hind wings of the Lepidoptera. In general the structure of these is 

 much like that of .similar organs in various parts of other insects, such as in 

 the bases of wings, appendages of other sorts such as antenn*, mouth parts, 

 legs and in the abdomen. The function of these structures with a tympanum 

 such as the author describes in some Lepidoptera has been thought to be for 

 hearing, those without this membrane are not so well understood. The 

 hypothesis of Loeb and others which considers these simpler organs to be 

 static, the author believes has much to support it. 



As to the organ in Lepidoptera, there is no proof that it is for hearing, 

 or indeed that these animals have such a sense. Especially in satyrs where 

 there is a good tympanic membrane, it seems there is at least an organ for 

 perceiving sound, whether it be noise or tone is, however, a harder question. 

 As others have mentioned, the author considers the possibility of butterflies 

 perceiving tones or sounds not audible to the human ear. 



w. n. 



DAS GESCIILECIITSLEBEN DES DYTISCUS MAKGINALIS L. 

 ]. TEIL DIE BEGATTUNG 



HANS BLUNCK 



Zeit. Wi.ss. ClI Bd., 2 Heft., 1912. 



In this paper there is a consideration of the periodicity of the mating 

 habits, a discussion of polygamy and polyandry. There are descriptions and 

 figures of the male and female sexual organs and a consideration of the sexual 

 habits and fertilization. Abnormal sexual parts are also considered. 



W. H. 



