DEVELOPMENT OF PARA VORTEX GEMELLIPARA 



493 



b. Maturation. Patterson described an achromatic figure 

 as appearing in the egg before it leaves the ovary, and remaining 

 until after the formation of the capsule. In his paper ('12) 

 on Graffilla (Paravortex) gemellipara he gave some space to 

 an account of this spindle, noting the remarkable characteristics 

 of its behavior. Although he believed at that time that the 

 spindle later disappeared, he came to the conclusion after a 

 study of the uterine spindle of Planocera that it was not entirely 

 eliminated, but simply contracted to so small a size as to es- 

 cape easy detection, and was only an early condition of the 

 maturation spindle. 



sfr. 



Text fig. 4 Section through two recently fertilized eggs of one capsule. Yolk 

 and capsular membrane not shown, mit., mitochondrial mass; sp., spermato- 

 zoon. X 730. 



Although occasionally a faint suggestion of a radial arrange- 

 ment of the granules is perceptible in the yolk-nucleus mentioned 

 above, in all my material no egg shows a true spindle until it 

 has left the ovary and has become surrounded with yolk cells 

 in the distal end of the antrum. It has, of course, for some- 

 time been accessible to spermatozoa. A single egg was ob- 

 served thus enclosed in loosely massed vitelline cells. It con- 

 tained a large spindle occupying nearly the entire diameter of 

 the egg. An exact count of the chromosomes in this spindle 

 is impossible on account of poor preservation, but certainly 

 more than the reduced number, four, are present This fact. 



