No. 611] GENESIS OF ORGANIZATION OF INSECT EGG 661 



period differ from the other cells in the body in the fol- 

 lowing ways, (1) In all cases where germ-line determi- 

 nants occur the oocytes alone are provided with them and 

 with the cytoplasm in which they are embedded. (2) In 

 insects like Miastor el full amount of chromatin is present 

 only in the oocytes. (3) In Dytiscns, Dineutes and prob- 

 ably other insects the oocytes contain nuclear material of 

 which the nurse cells are deprived, but this may be in- 

 terpreted simply as a means of inhibiting the reproduc- 

 tion of the latter and of changing them into nurse cells. 

 (4) The oocytes seem to have no influence upon the de- 

 velopment of the individual in which they lie, as indicated 

 by castration and transplantation experiments,-® and are 

 in a comparatively undifferentiated condition when the 

 growth period begins. 



26 Meisenheimer, 1912, Fest. 60 Geburtstage von Dr. J. W. Spengel III.,' 

 Kopec, 1911, Arch. Entev.-mech., Bd. 33. 



(To ie continued) 



