48 BIOLOGICAL LECTURES. 



There is a third view regarding the relative values of the egg 

 and sperm centrosomes. You are familiar with it under the 

 name of " Fol's quadrille of the centres." This view has been 

 attacked repeatedly during the past year; in fact, the attack on 

 the " quadrille of the centres " might be appropriately called 



FIG. 2. Optical section of entire egg, showing head of spermatozoon, fertilization cone, first matu- 

 ration spindle with attraction spheres and archoplasm in the spheres, cone, spindle, and 

 throughout the cytoplasm (microsomes not represented). 



the latest cytological fad. It seems to be the fashion, " the 

 mode " (they do us biologists great injustice when they accuse 

 us of scorning such things). 



It seems to me that discussion as to the role played by the 

 egg and sperm attraction sphere is of no especial value until 

 we know something more definite concerning the origin of their 

 two centrosomes. Has the male centrosome a different origin 



