174 PROCEEDINGS OF THE ACADEMY OF [Feb., 



chromosome, one univalent chromosome is turned toward one spindle 

 pole and the other toward the opposite one, and each univalent chro- 

 mosome being longitudinally split the linin thread attaching it to the 

 spindle pole must be split into two ; for any longitudinal splitting of 

 the chromatin globules is always associated with, if indeed not induced 

 by, a splitting of the linin matrix, as is shown in the details of chro- 

 mosome formation, especially in the post-synapsis stage. If the first 

 maturation division were equational there would be no adequate 

 explanation for the double mantle fibres. As the centrosomes of the 

 second spermatocyte move apart preparatory to the second matura- 

 tion mitosis, each carries along with it one of the two mantle fibres 

 attached to each chromosome. 



2.— Spermatogenesis of Lycosa insopita Montg. 



The only published work upon Aranese is that of Carnoy (18S5), Wag- 

 ner (1896) and Wallace (1900). Miss Wallace's paper was done partly 

 under my direction, and is a short preliminary note dealing with the 

 accessory chromosomes, which she correctly found to be double in the 

 spermatocytes, but did not determine positively its behavior in the 

 maturation mitoses. Wagner's short paper I have not at hand, and 

 cannot now recall his conclusions. Carnoy described quite minutely the 

 process of cell division in male germ cells of a number of spiders, of Phal- 

 angium and Scorpio, illustrating both spermatogonic and spermatocytic 

 divisions (his whole plate V with its numerous beautiful figures) ; such 

 work has no direct bearing upon modern spermatogenetic study, in that 

 it does not consider the sequence of changes through the several cell gene- 

 rations. But it is but just to say of this study of this priest of Lou- 

 vaine, that it was in many respects the best work of its day upon cell 

 division. Most writers, following a certain antiquated German school, 

 have neglected to refer to him. But he pointed out that cell division 

 is not all of one kind, but that two main types of it occur, and this we 

 now know to be the case and term them respectively reduction and 

 equation divisions ; yet this was the main ground on which that particu- 

 lar German cult fought him. And he undoubtedly saw much more 

 than many a later investigator, and lacked only a general standpoint 

 of interpretation. 



Testes w^ere studied of an adult male caught in October; they were 

 fixed and stained by the methods used for Syrbula. The testes are 

 slender, cylindrical tubes, and on account of the difficulty of removing 

 them entire from the fresh animal, one proceeds best by cutting off the 

 abdomen from the living animal, removing the h3qpodermis, fixing the 



