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FRANK K. LILLIE. 



spindle (Fig. 2). What happens when they are driven into the 

 area of the karyokinetic figure ? A few examples will illustrate : 

 The egg shown in Fig. 8 was allowed to stand in sea-water 

 about 35 minutes, then centrifuged 1,150 revolutions in 31 sec- 

 onds at a radius of 13 cm. and killed as rapidly as possible in 

 picro-acetic acid. It was one of a large number. Sections were 

 cut 6 fjt thick and stained in iron haematoxylin and orange G. 



FIG. 8. Section of an egg of Chatopterus centrifuged 1,150 revolutions in 31 sec- 

 onds at a radius of 13 cm. Half of the karyokinetic figure lies in the basophile cap.. 

 See text for further description. 



All the sections of this egg are present on the slide. The figure 

 represents a single section which includes practically the entire 

 spindle and all nine chromosomes. The plane of the section was 

 nearly transverse to the axis of stratification and is approximately 

 tangential to the basophile cap ; but on the right side the sec- 

 tion passes nearer to the distal pole than on the left side and 

 therefore takes in a good deal of the distal acidophile stratum on 

 this side, while on the left side the section is confined to the 



