KARYOKINETIC FIGURES OF CENTRIFUGED EGGS. 



105 



line of action of the centrifugal force, owing to the differential 

 force between centripetally and centrifugally moving granules ; 

 (2) the principarpart'of this elongation is born by the massive, 

 external, more fluid zone, which is stretched more on the centrip- 



hb 



FIG. 2. Section of an egg of Chatopterus centrifuged 1,150 revolutions in 31 sec- 

 onds at a radius of 13 cm. 2-2 indicates the direction of the centrifugal force ; 5, 

 ectoplasmic zone; b.c., basophile cap; g.c., gray cap, or fatty granules (dissolved 

 out by the oil used in preparation); h.b., hyaline band; s.a., spongy area. This 

 egg was stained in iron hrematoxylin and orange G. 



etal side, the consequence being that the inner fluid area and its 

 dense bounding zone lie on the centrifugal side of the middle 

 point of the elongated egg (Figs. 3 and 4). 



The spindle itself may be moved as a result of centrifuging. 

 The simplest cases are those in which the outer end remains fixed 

 and the inner end is swung from its radial position. This shift- 

 ing appears to be due to distortion of the ground substance with 



