THE SPERMATOGENESIS OF THE MYRIAPODS. 



v. — ON THE SPERMATOCYTES OF LITHOBIUS.^ 

 By Mauls by W. Blackman. 



Presented by E. L. Mark, December 12, 1906. Received November 22, 1906. 



For a number of years the author has been collecting material for a 

 comparative study of the spermatogenesis of the principal groups of the 

 Chilopoda. Five papers based upon this material have already been 

 published; a series of four papers (Blackman, :0l, :03, :05, :05*) upon 

 two species of Scolopendra (S. heros and S. subspinipes) and one paper 

 upon Scutigera forceps by Medes (:05). In the present article it is my 

 purpose to carry this comparative study further. 



The present paper is based upon a study of the spermatocytes in 

 three species of the genus Lithobius and is from material collected 

 in three widely separated localities. The principal observations were 

 made on the testes of Lithobius mordax, collected in the vicinity of 

 La\vrence, Kansas, during the spring and summer of 1902 and 1903. 

 Using as a basis the knowledge gained from the study of this species, 

 additional observations have been made upon Lithobius sp. 1 and 

 Lithobius multidentatus, with a view to comparison. The material 

 of Lithobius sp. 1 was collected by the author near Flatts, Bermuda, 

 during July, 1903, while working at the Bermuda Biological Station for 

 Research ; that of Lithobius multidentatus was collected near Cambridge, 

 Mass., during October, 1904. 



At the time this comparative study of myriapod spermatogenesis was 

 begun, no detailed work upon the germ cells of chilopods had been at- 

 tempted under modern conditions of technique. The only observations 

 upon this material then published were those of Carnoy ('85) in his 

 classical Cytodierfese chez les arthropodes, and those of Frenant ('87, '92). 

 Since then, however, a number of papers based upon the sperm cells of 

 myriapods have appeared. Of those dealing with problems touched 

 upon in this article the chief are those by Meves and von Korff (Litho- 



^ Contributions from the Bermuda Biolot;ical Station for Research, Xo. 10; and 

 from the Laboratory of Histology and Embryology, Western Reserve University. 



