and Laboratory Methods. 1385 



CURRENT ZOOLOGICAL LITERATURE. 



Charles A. Kofoid. 



Books and separates of papers on zoological subjects should be sent for review to 

 Charles A. Kofoid, University of California, Berkeley, California. 



Bergh, R. S. Kleinere histologische Mittheil- The author commends the use of 

 ungen, Zeitsch. f. Wiss. Zool. 69 : 444-456. maceration methods in the study of 

 Taf. 32, 33, 1 90 1. ^^g histology and organology of the 



larva of the leech Aulastoma. Very dilute acetic acid or a mixture of three or 

 four parts of 30 per cent, alcohol with one part of '1 per cent, acetic acid was 

 employed with good results, both for maceration and as a fluid for examination. 

 For the demonstration of cell boundaries the silver method of Fischel was used, 

 though the finest results were secured with a mixture of equal parts of 1 per 

 cent, nitric acid and 1 per cent, silver nitrate allowed to act for a longer time 

 than that usually employed in silver impregnation. Reduction was accomplished 

 by sunlight or by a weak solution of formic acid in alcohol. By this 

 method very fine demonstrations of the cell boundaries in the nephridia of the 

 Lumbricidce can be secured, the cell limits being defined even in the intra- 

 cellular lumen. Bergh confirms his earlier thesis of the presence of a larval 

 epidermis in Aulastoma consisting of about thirty large multinucleate cells, 

 whose nuclei multiply by amitotic division. The structure of the nephridium of 

 Lumhricus hcnuleus is considerably elucidated by the silver method. The cells 

 in the margin of the funnel alone have the usual straight cell walls. Within the 

 funnel and in the straight, ciliated, intracellular lumen of the adjacent section of 

 the nephridium the cell walls are very tortuous. In the narrower regions when 

 the lumen is intracellular they become even more irregular and in the ampulla 

 almost labyrinthine, though everywhere transverse in general direction, each 

 cell forming a short transverse section of the nephridial tube. Attempts to 

 demonstrate cell boundaries in the nephridia of the aquatic oligochaites by the 

 silver method failed entirely. c. a. k. 



Coe,W.R. Papersfrom the Harriman Alaska ^r. Coe reports thirty-twO species, of 

 Expedition, XX. The Nemerteans, Proc. which all but tWO are new tO the 



Wash. Acad. Sci. 3: i-i 10, pi. 1-13, iqoi . t-. -c • 1 ^ ^ 



^ ^ ^ Pacmc region and twenty-seven new to 



science. The methods employed with this refractory group are of general 



interest. The worms die well extended if a few drops of formalin are added to 



the sea water in which they are placed, and if handled with care they do not 



always break up into fragments. Material was hardened in 2 to 5 per 



cent, solution of formalin in sea water and eventually transferred to alcohol. 



Formalin gives good results for anatomical work or for the histology of epithelial 



structure, but it is disastrous to the connective and nervous tissues. For 



supplementary work, strong alcohol, sublimate-acetic, Gilson's fluid, and — for 



nervous system — Flemming's fluid were used. Iron hematoxylin followed by 



orange G was the most effective stain for sections. c. a. k. 



