MITOTIC FIGURE IN OOCYTE OF CANTHOCAMPTUS. 



323 



plate of the first polar mitotic figure. The number of chromo- 

 somes was not determined. The nucleolus, which stains very 

 deeply in the growing oocytes, is lighter in the primary oocytes, 

 and often has several vacuoles with- 

 in it. In a few cases two nucleoli, 

 one larger than the other, were 

 found in a single nucleus. Fig. 2 

 shows the various cellular structures 

 as they appear when magnified 850 

 diameters. 



A discussion of the above de- 

 scribed condition in its relation to 

 amitosis and other nuclear pheno- 

 mena is deferred in the hope that 

 material collected later in the sea- 

 son may furnish stages which will 

 enable me to follow the history of 

 the formation and the fate of this unique mitotic figure. 

 Zoological Laboratory, 



University of Wisconsin, 

 March 13, 190S. 



LITERATURE. 

 Brauer, A. 



'93 Zur Kenntniss der Spermatogenese von Ascaris megalocephala 

 Mikr. Anat., Bd. 42. 



Hacker, V. 



'gz Die Eibildung bei Cyclops und Canthocamptus. Z. Jahrb. Morph., Abt., 



Bd. 5. 

 '95 Die Vorstadien der Eireifung. Arch. Mikr. Anat., Bd. 45. 



McClendon, J. 



'06 On the Development of Parasitic Copepods. Biol. Bull., Vol. XII. 



Riickert, J. 



»94 Zur Eireifung bei Copepoden. Anat. Hefte, X Abth., Bd. 4. 



Fig. 2. A single oocyte of Can- 

 thocamptus staphylinus Jur. enlarged 

 from Fig. I, a. The entire am- 

 phiaster lies within the nuclear mem- 

 brane. X 850. 



Arch. 



