AUTHOR S ABSTRACTS OF THIS PAPER ISSUED 

 BY THE BIBLIOGRAPHIC SERVICE, MAY 1 



THE CLOACA AND CLOACAL GLANDS OF THE MALE 

 NECTURUS 



ALDEN B. DAWSON 



Depariinenl of Analomy, Loyola University School of Medicine 



THREE PLATES (siXTEENT FIGURES) 



INTRODUCTION 



At present the mating habits of Necturus are not definitely 

 known. Strong circumstantial evidence indicates (Kingsbury, 

 '95) that fertiUzation is accompHshed by the deposition of sperma- 

 tophores and the reception of the spermatozoa which are borne 

 upon the summits of the deposited spermatophores into the 

 cloaca of the female. The time and the exact manner of in- 

 semination are not known. An abundance of spermatozoa was 

 found by Kingsbury ('95) in the spermathecae of six females 

 which he examined during the late fall and winter. Females 

 examined by the writer in October and INLarch were found also 

 to have large numbers of sperms in their spermathecae. Ac- 

 cording to Smith ('11), fertilized eggs are deposited chiefly dur- 

 ing May and June. 



Although our information on the time and manner of fertili- 

 zation is still incomplete, it seems highly probable that sperma- 

 tophores are produced by the male Necturus. The matrix of 

 the spermatophores is probably a product of the cloacal wall 

 acting in conjunction with the surrounding masses of tubular 

 glands. The degree of glandular activity in this region should 

 furnish therefore some clue as to the probable time of spermato- 

 phore deposition. With this in mind, a study of the cloaca was 

 undertaken. Owing, however, to the complexity of the internal 

 configuration of the cloaca, the complicated relations of the clo- 

 acal wall to the tubules of the surrounding gland masses, and the 

 many varying types of tubules encountered, the comparative 

 study of the glandular activity at different times of the year had 



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