640 SUMMARY OF CUKRENT RESEARCHES RELATING TO 



Anatomy of Spiders.* — Dr. F. Dahl reviews certain statements of 

 Bertkau with respect to the anatomy of spiders. This observer has 

 mentioned that salivary glands have not been figured ; Dahl calls 

 attention to the fact that he has himself observed and figured them in 

 E]peira cornuta, in the males of which species they are far better 

 developed than in the females ; this may be accounted for by the fact 

 that the mature male takes little or no nourishment while the female 

 after depositing her eggs spins a web and catches and devours insects. 

 The paper contains rectifications of a few other statements made by 

 Bertkau which are believed by Dahl to be erroneous. 



Hibernation and Winter Habits of Spiders.f — The Eev. Dr. 



McCook describes some observations on this subject. In the case of 

 Theridion tepeclariorum it would seem that the hibernation is not 

 accompanied with a great degree of torpidity ; that the spiders pre- 

 serve their activity and spinning habit while exposed to cold ranging 

 from freezing point to zero (Fahr.) ; that; after long and severe 

 ■exposure, the recovery of complete activity when they are brought 

 into a warm temperature is very rapid, almost immediate ; and that 

 on the return of spring, even after a prolonged and severe winter, 

 they at once resume their habits. 



In all the specimens experimented on the abdomens were full, 

 indicating perfect health. Other spiders hung upon their webs with 

 shrivelled abdomens, quite dead ; but the author could not determine 

 that they perished by the cold. There appeared to be no growth 

 during hibernation. The same facts hold good as to the winter habits 

 of orb-weavers. The young survive in the cocoons provided by 

 maternal instinct. But early in the spring many adults of both sexes 

 are found, who have also safely weathered the cold months. Many 

 specimens of Epeira vulgaris shelter within a thick tubular or arched 

 screen, open at both ends, which is bent in the angles of woodwork, or 

 beneath an irregular rectangular silken patch stretched across a 

 •corner. Many others burrow behind cocoons, and are quite covered 

 up by the thick flossy fibre of which these are composed. Examples 

 of E. strix were found blanketed in precisely the same way during the 

 winter months. 



e. Crustacea. 



Urinary Organs of Amphipoda.^ — Mr. W. Baldwin Spencer finds 

 that little is stated in the text-books as to the presence in certain 

 Orustacea of small but well-defined appendages which open into the 

 posterior part of the alimentary canal ; the best method of examining 

 these tubes is to cut sections through the whole of the body, when 

 the course that they take and their relation to the neighbouring 

 organs can be easily made out. 



The author has carefully investigated the tubes of Talitrus locusta ; 

 the walls were found to be cellular in nature, and within these were 



* Zool. Anzeig., viii. (1885) pp. 241-3. 



t Proc. Acad. Nat. Sci. Philad., 1885, pp. 102-4. 



X Quart. Journ. Micr. Sci., xxv. (1885) pp. 183-92 (1 pi.). 



