5H Edmund B. Wilson. 



FIGURE I. 



Alydus pilosulus. a, Contraction-phase of synaptic period, "accessory" (h) in the form of a con- 

 densed chromosome-nucleolus attached to a large plasmosome (/>); b, spermatocyte-nucleus, middle 

 growth-period, showing large diffused chromosomes "accessory" still attached to the plasmosome 

 and the two condensed m-chromosomes on opposite sides of the nucleus; c, early proph?se of first 

 division, showing all of the chromosomes, the larger ones condensing; d, late prophase, showing 

 "accessory'' (h) and the two w-chromosomes still separate; e, slightly later prophase, showing all 

 of the chromosomes; /, initial anaphase, first division, the w-chromosomes separating; g, polar view of 

 metaphase-group, first division; h, polar view of metaphase-figure, second division; /', j, initial 

 anaphases, second division; k, spermatogonial metaphase-group; /, m, n, o, anaphases of second 

 division. 



