" heterotypical" mitosis in nereis limb ata. 83 



v. Winiwarter, H. 



'01 Recherches sur l'ovogenese el l'organogenese de l'ovaire des Mammiferes. 

 Arch. deBiol., T. 17. 



To the Plates, pp. 62-63. 



The chromosomes represented in these plates are selected from among a great 

 number of camera drawings which will be published in a following paper. 



They are all drawn to the same scale, enlargement about 3,500 : 1. 



The chromosomes of the first maturation division are continuously numbered ; some 

 of these numbers being applied also to chromosomes of the later divisions, showing 

 essentially the same structure as those of the first. 



The letters- a and a are applied to the morphologically distinguishable halves of 

 the chromosomes, demonstrating their reappearance in each group of divisions, but 

 without any interpretation concerning the meaning of these structures. 



The relatively larger size of the chromosomes of the later cleavage divisions (7 to 

 15 h. aft. fertil.) may be due to their fixation in Flemming's fluid, while those of the 

 maturation and the early cleavage are fixed in picro-acetic acid. 



