240 
SIDNEY I. KOKNHAUSER 
chromosomes, being purple in crystal violet + alizarin, and red 
in methyl green + acid fuchsin. The use of these stains enables 
one to establish the number twenty-five for the spermatogonial 
chromosomes. As will be shown later, twenty-two of these are 
autosomes, two form an x-complex, and one is a y-chromosome. 
The male somatic number was likewise established by the study 
of serial sections of embryos in which many counts of single 
individuals were made. Figures 13 to 16 (Plate XXIV) are typical 
25 chromosome plates of such male embryos. The following 
important variation, the only characteristic one so far found in 
the study of Anisolabis, must be noted. In male embryos, with 
typical 25 chromosome cells, one finds clear metaphase plates 
with only 24 chromosomes. This happened too often to be purely 
accidental or due to error or oversight. A probable explanation 
of the phenomenon will be given in Part 8. 
6. THE SPERMATOCYTE CHROMOSOMES 
The initial and most fundamental facts to be established were 
that twelve chromatic elements were uniformly present in prim- 
ary spermatocyte metaphase plates (Plate XXV, figs. 28-29), and 
that half the secondary spermatocytes possessed twelve chromo- 
somes and the other half had thirteen (Plate XXVI, figs. 44-47). 
These facts made necessary the careful study of the origin of 
the twelve primary spermatocyte chromosomes. 
From the 25 spermatogonial chromosomes are formed eleven 
autosomal tetrads and a heterochromosomal hexad, which I 
have called the xxy-complex and which may be seen in figures 
17-27 (Plate XXV). The autosomal threads and tetrad forma- 
tion are omitted from these figures. The evidence is rather clear 
that the tetrads are formed by parasyndesis, and it is hoped that 
additional smear preparations will enable the author to deal 
with this point in more detail in another paper. Figures 17-22 
show merely the nuclear outline and the xxy-complex, stained in 
iron-haematoxylin, the relative intensity of the stain being 
depicted as accurately as possible in the figures. 
Figure 17 is an early leptotene stage, the autosomal threads 
just emerging from the telophase chromosomes of the ultimate 
