476 FOOT. [VoL. IX. 
The same method of staining applied to the spermatozoa.in 
these two stages produces very different results. In the first 
Fic. 1. Optical section of entire egg, showing three spermatozoa entering egg, 
three cones, nucleoliin the cytoplasm, sperm granules, and first maturation spindle. 
stage the tail does not stain; in the second the head and tail 
stain with equal intensity. 
From one to three spermatozoa may enter an egg, each pass- 
SR SD ae LS pT A 
Fic. 2. Spermatozoon obtained about two hours before deposition of cocoon 
— showing spine, head, middle piece and tail. 
ing through like stages of development until it has attained 
the pronucleus stage. 
The normal time of entrance seems to be after the first 
maturation spindle has reached the periphery of the egg, but 
before its division. In some cases, however, they penetrate 
later, as several specimens show the first polar body already 
