2290 Journal of Applied Microscopy 



CURRENT ZOOLOGICAL LITERATURE. 



CHARLES A. KOFOID, University of California. 



Books and Separates of Papers on Zoological Subjects should be Sent for Review to Charles A. 

 Kofoid, University of California, Berkeley, California. 



^ , ,. ^ „ ., , . . , „ , . The eggs of Crepidula are most favor- 



tonklii], b. u. Karyokinesis and Cytokinesis °° ^ 



in the Maturation, Fertilization and Cleavage able for the study of cleavage. They 

 of Crepidula and other Gasteropoda Journ. ^j.g enclosed in membraneous capsules 

 Acad. Nat. Sci. Phila. 12: i-i 24, 6 pis., 1902. _ ^ 



which reagents readily penetrate. Eight 



to ten thousand eggs may be secured from a single female, 175 eggs being found 

 in a single capsule of C. plana. The eggs are small (.136 mm.), of uniform size, 

 and contain much yolk, which stains heavily with most stains. For the study of 

 entire eggs the author teased the living eggs from the capsules into Kleinen- 

 berg's picro-sulphuric mixture or Boveri's picro-acetic, where they were left for 

 thirty minutes to two hours. They are then washed in alcohol until they become 

 white and are stained for five to ten minutes in the following solution : Dela- 

 field's haematoxylin 10 cm.^, distilled water 40 cm.^, Kleinenberg's picro-sul- 

 phuric fluid 1(> drops. Eggs so stained are washed in alcohol, dehydrated and 

 mounted in balsam. Eggs of C. plana mounted under a thin cover supported 

 at one side by a bit of glass .15 mm. thick can be studied with an oil immersion 

 lens and the relative positions of the nuclear structures determined, as would be 

 impossible in sections. This stain leaves the yolk a transparent yellow, colors 

 the protoplasm a rosy tint, while chromatin, centrosomes, and mid-bodies are 

 blue or black. The method is recommended for eggs of mollusks, annelids and 

 arthropods where there is much yolk. Eggs fixed in Kleinenberg's fluid are 

 more transparent than those in Boveri's picro-acetic, but the cytoplasm is better 

 preserved by the latter. For sectioning the following fixing fluids gave good 

 results : Flemming's, Hermann's, Boveri's picro-acetic, Graf's picro-formol, 

 while a long list of well known fluids gave inferior results. The best results 

 were secured by fixing in Boveri's picro-acetic and staining in Delafield's haema- 

 toxylin and orange G. Iron haematoxylin and Bordeaux red also gave good 

 results, though obscuring centrosomes and asters in the yolk, which stains heavily 

 and resists de-staining. Hermann's safranin-gentian-iodine, Biondi-Heiden- 

 hain's mixture, Auerbach's acid fuchsin and methyl-green and other stains were 

 also used. Sections were wont to crumble on account of yolk. This was 

 obviated by double embedding in celloidin and paraffin by Kultschitzky's method, 

 though sections of such material are much folded and are with difficulty flat- 

 tened, c. A. K. 



Harmer, S. F. On the Morphology of the Alcoholic material was used for this 

 Cheilostomata. Quart. Journ. Mic. Sci. N. investigation, and the growing edges 



of healthy colonies were selected as 

 yielding most satisfactory results. The material was stained without decalcifica- 

 tion in dilute borax carmine for 5 to 7 days, and dehydrated in absolute alcohol to 

 which picric acid had been added, and then mounted whole in balsam, Speci- 



