PLATE 2 
EXPLANATION OF FIGURES 
5cand5d_ From two eggs thirty-seven minutes after insemination; cf. 5 a@and 
5b. 
6 Forty-eight and one-half minutes after insemination. The entrance cone 
has begun to sink into the egg, drawing the head of the spermatozo6n after it. 
7 Forty-eight and one-half minutes after insemination. Later stage of pene- 
tration of the spermatozoodn. 
8 Forty-eight and one-half minutes after insemination. Still later stage of 
penetration. 
9aand9b. Two drawings of the same section; 9 @ drawn with Zeiss 2 mm. 
apochromatic objective and no. 4 compensating ocular; 9 b, the part of 9 a contain- 
ing the spermatozo6n, drawn with Zeiss 1.5 mm. apochromatic objective and no. 
12 compensating ocular. Fifty-four minutes afterinsemination. ‘The sperm head 
has completed its penetration, and its base is some distance from the periphery; 
but the middle-piece remains outside. Anaphase of the first maturation division. 
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