1542 



Journal of Applied Microscopy 



Petersen, C. G. J. An Otter-Seine for the Ex- The problem of capturing the larger 

 ploration of the Deeper Seas. Rep. Danish , ^. • u !_•.. ^ c ^\ 



Biol. Sta., 8: 24 pp., 4to, 10 figs., 1899. and more active inhabitants of the sea 



bottom has been attacked in the past 

 by large beam trawls. These are limited in size, the largest being 10 to 15 feet 

 beam, and are difficult to manceuver, even with large vessels. The beamless 

 trawling gear used of late by North Sea trawlers has been adapted by Dr. 

 Petersen to biological work. With a 32-foot steam launch he operated, in depths 





Sailing Vessel with Otter Drag-Seine. 



of 1 to 300 fathoms, a trawling gear of this pattern whose spread at ordinary 

 speed was 12 to 16 feet. With a more powerful craft and larger trawl a much 

 greater speed can be secured. Two boards, 29 x 32 inches, with iron runners, 

 are attached to the ends of the wings of the bag, which is provided with a light, 

 collapsible funnel. The mouth of the bag is kept in shape by suitable weights 

 and Norwegian glass floats. From the boards pass bridles, eight fathoms long, to 

 the vertex of the crow-foot, where a shackle, float, and lead keep the bridles 

 from twisting. From the vertex a single line passes aboard ship. A proper ad- 

 justment of speed is necessary to secure the most successful operation of the 

 trawl. The figure gives some idea of the trawl in action. Full directions for 

 knitting the bag are given in the original article. The catches of this apparatus 

 are said to be phenomenal. c. a. k. 



Bock, M. de. Observations Anatomiques et ^^^e author seeks to clear up some con- 

 Histologiques sur les Oligochetes Speciale- 



ment sur leur Systeme Musculaire. Rev. troverted points concerning the muscu- 

 Suisse de Zool. 9: 1-41, pl. i, 2, 1901. \^x^^x^ of the OUgochceta, employing as 



objects of study a number of different terricolous and limicolous species. The 

 study of sections was supplemented by the examination of material prepared 

 by maceration for several months in a ^ to 1 per cent, solution of bichromate 

 of potash and then disassociated, after several weeks, in glycerin. The silver 

 nitrate method of Dekhuyzen was employed to demonstrate the membrane of the 

 so-called sarcolemma. The muscle columns (colonnes musculaires of Cerfon- 

 taine) which constitute the musculature of the body wall of the Oligochceta are 

 composed of bundles, each containing a small number of fibers, and are enclosed 



