The spermatogenesis of the pribilof fur seal (Callorhinus Alascanus Jordan and Clark)

Abstract

THREE PLATES (FIFTY-SEVEN FIGURES)The material assigned to me by Dr. F. M. McFarland for this study was preserved in the Pribilof Islands by Mr. G. A.Clark, special assistant in charge of fur seal investigations, and consists of small portions of freshly preserved testes of three-and eight-year-old fur seals, Callorhinus alascanus Jordan and Clark. All stages are found in material from each individual, and correlated with findings in testes from other ages put up some years previously by Mr. Clark, so that observations are based upon a study of preparations from both individuals. TECHNIQUEThe fixatives used were strong and weak Flemming. Bouin 's picro-f orrnalin acetic, sublimate-alcohol-acetic, Hermann's fluid, and saturated corrosive sublimate, the best results being obtained from Flemming's and Hermann's fisation. Paraffin serial sections were cut ranging from 3 t o 10 p in thickness, 5 p being found most satisfactory. Of the stains used, iron haematoxylin without counterstain gave the best definition. Chromotrope 2B, acid fuchsin, orange G, were good counterstains, while safranin, Mann's methyl-blue eosinate, Flemming's triple stain, and Delafield's haematoxylin were used in investigating certain points. 471