152 Edmund B. Wilson 



EXPLANATION OF FIGURES 



Fig. I 



About one-fourth of the figures were drawn upon enlarged photographs by the method described 

 in a preceding paper (Wilson '09). The others are from camera lucida drawings. In all cases the form, 

 size, and grouping of the chromosomes are represented as accurately as possible. The form, size, and 

 general appearance of the spindles are shown, but no attempt has been made to represent the exact details 

 of the fibrillae. Figs, i and 2 are enlarged about 3300 diameters, the others a little less than 3000 

 diameters. 



Lettering, in all the Figures 



I, large idiochromosome or odd chromosome; ;', small idiochromosome; m, m-chromosome; p, plas- 

 mosome; s, supernumerary chromosome. In cases where s and / are both present and of equal size it is 

 impossible to distinguish between them. In such cases I have as a rule designated as /' the one lying 

 nearest to I; but this is quite arbitrary. It should be noted also that I cannot always be distinguished 

 from the smaller of the ordinary bivalents. 



