Centrifugal Force upon Beetles^ E'KS^ 



523 



it fell outside of those sections containing parts of the gray cap 

 so that I was unable to determine whether it is of greater or less 

 specific gravity than the later substance. 



C.B. J, c, d, e, and f. These eggs did not develop very far, 

 although the youngest (3, c) contained a number of nuclei in 

 the course of disintegration. Sections of the other eggs (3, d, e 

 and /) show a further dissolution of the nuclei, the vacuolation of 

 the "Keimhautlbastem" and other evidences of catabolism. 



TABLE \s 



Calligrapha higshyana — Series C.B. lo 



Interval 

 Number of Age when cen- Length of time between end of 

 experiment trifuged I centrifuged experiment and 



fixation 



Orientation 



Remarks 



C.B. 10, a 

 C.B. 10,6 

 C.B. 10, c 

 C.B. 10,^ 

 C.B. 10, e 

 C.B. 10,/ 

 C.B. 10, g 

 C.B. 10, h 



Control 



* This means that the right side of the egg was placed toward the axis of rotation. 



Series C.B. 10— Table IV 



These experiments were undertaken to detemme if the position 

 of the embryo upon the egg can be changed by altering the distri- 

 bution of the cytoplasm. Four of the eggs were oriented in the 

 centrifugal machine so that their right sides were toward the axis 

 of rotation, the other three with their ventral surfaces toward the 

 center. 



C.B. 10, a. The control egg was in an early cleavage stage. 



C.B. 10^ b and c. No differences could be discovered between 

 an egg centrifuged with its right side turned inward and one with 

 its ventral surface in the same direction, either before or after 



