524 University of California Publications in Zoology [VOL. 11 



threads has a relatively much longer duration than any other of 

 the stages of the prophase of the first maturation division. If 

 it is true that the conjugating threads have the value of paired 

 maternal and paternal chromosomes and constitute the mechan- 

 ism for the segregation and recombination of mendelian char- 

 acters or their factors, it is to be noted that there is ample 

 opportunity for the reconstitution of the chromosomes and for 

 any interchange of substances composing the chromosomes which 

 may be concerned in the transmission of inherited characters. 



SUMMARY 



1. The usual number of chromosomes found in the sperma- 

 togonia of Aneides lugubris is twenty-eight. 



2. The V-figures at the beginning of polarization number 

 twenty-six to thirty, and Ys at a slightly later stage twenty-eight. 



3. The number of polarized loops and of tetrads formed from 

 the loops is fourteen. 



4. Each tetrad is the result of a parasynaptic union of fine 

 threads. 



Transmitted May 3, 1913. 



LITERATURE CITED 



ElSEN, G. 



1900. The spermatogenesis of Batrachoseps. Journ. Morph., 17, 1-117, 



pis. 1-14, 12 figs, in text. 

 FICK, E. 



1908. Zur Konjugation der Chromosomen. Arch. f. Zellforsch., 1, 



604-611. 

 FLEMMING, W. 



1887. Neue Beitrage zur Kenntnis der Zelle. Arch. f. mikr. Anat., 

 29, 389-463, pis. 23-26. 



GOLDSCHMIDT, B. 



1906. Eeview of work of the Schreiners. Zool. Centralblatt, 13 



611-612. 

 1908. 1st eine parallele Chromosomen-konjugation bewiesen? Arch. 



f. Zellforsch, 1, 620-622. 

 JANSSENS, F. A. 



1901. La spermatogenese chez les tritons. La Cellule, 19, 7-116, 3 pis. 

 1905. Evolution des auxocytes males du Batrachoseps attenuatus. Ibid., 



22, 377-425, 7 pis. 



