THE SPERMATOGENESIS OF BUFO LENTIGINOSUS. 
BY 
HELEN DEAN KING, Pu. D. 
WITH 3 PLATES AND 2 DIAGRAMS IN THE TEXT. 
Although the spermatocytes of amphibians seem to be exceptionally 
favorable material for a study of maturation phenomena, there has been 
considerable controversy among the workers on amphibian spermato 
genesis regarding the character of the maturation divisions. Several 
investigators, among whom may be mentioned Meves, McGregor, and 
Hisen, maintain that both of the maturation divisions are longitudinal ; 
Montgomery and vom Rath, on the other hand, claim that only one of 
the divisions is longitudinal, the other being a reduction division in the 
Weismannian sense. It seems necessary, therefore, that the behavior of 
of the chromatin in the germ-cells of more species of amphibians should 
be studied in order that this point may be definitely determined. 
With the exception of vom Rath (46, 47), Biihler (7), and Broman 
(6), the investigators who have recently studied the spermatogenesis 
of amphibians have worked on various species of the Urodela. Vom 
Rath’s study of Rana was very fragmentary and his results have been 
severely criticised; the researches of Bihler on Bufo vulgaris, and of 
Broman on Bombinator igneus, were confined to the development of the 
spermatid into the spermatozodn. The spermatogenesis of the Anura is, 
therefore, practically an unworked field. The present paper records 
investigations on the common toad, Bufo lentigimosus, which form the 
starting point for a study of the chromatin relations in the germ-cells 
of various species of amphibians. It is only by a comparative study of 
many forms that one can safely draw conclusions for an entire class. 
MATERIAL AND METHOD. 
Testes of adult toads killed at various times from April until Septem- 
ber, and also testes of young toads with a body length of from 2 cm. to 
6 cm. were used for these investigations. In both kinds of material 
like processes of development were found to be taking place, and it is 
evident that the spermatozoa formed anew each year in the adult undergo 
AMERICAN JOURNAL OF ANATOMY.—VOL. VII. 
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