242 II. M. KINGERY. 



ham ('08) describes very briefly a few stages of the prophase of 

 the first maturation division in this same form. 



Descriptions of the first and second polar spindles in normally 

 maturing oocytes do not agree. Sobotta ('07) says: "Wenn 

 auch namentlich die Breite individuell etwas wechselt, so betragt 

 Lange wie Breite des ersten Richtungsspindel der Maus doch 

 stets das Doppelte der Masse des zweiten Richtungsspindel, die 

 Breite ist in der Regel mehr als doppelt so gross." Lams and 

 Doorme, on the other hand, find that the first and second polar 

 spindles are of exactly the same length and diameter. They 

 state: "D'une facon certaine, tin ovule a second fuseau ne se 

 distingue d'un ovule a premier fuseau que par la presence, dans 

 le premier cas, du premier globule polaire." Kirkham agrees 

 with Sobotta in saying that the first polar spindle is larger than 

 the second and also in describing the chromosomes as differing 

 in size and shape in the two spindles. 



In regard to oocytes in atretic follicles, Athias says of the 

 spindle, first or second: "Sa forme et ses dimensions sont 

 variables, mais il n'y a pas des caracteres qui soient propre au 

 premier ou au second fuseau; la presence concomitante d'un 

 premier globule polaire est, d'apres ce que j'ai pu constater dans 

 mes preparations, le seul criterium pour affirmer si Ton est en 

 presence d'un second fuseau de direction." In my own prepara- 

 tions the lengths and diameters of a number of first and second 

 polar spindles in atretic oocytes were measured. For the first 

 polar spindles, the average length was found to be 24.7 AI, the 

 diameter 12.8 ju, while for the second, the average length was 

 25.9 ju and the diameter 8.7 /*. Allowing for error in measuring, 

 the spindles are seen to be of about the same length, while the 

 second polar spindles are about two thirds the diameter of the 

 first. 



In degenerating oocytes of the white mouse the first polar 

 spindles are found to be of two general forms: slender, with the 

 achromatic fibers meeting at a point at each end, and thick, 

 "barrel-shaped," with broadly rounded ends. These two kinds 

 are met with in about equal numbers. In both, the chromosomes 

 are arranged with their long axes parallel to that of the spindle. 

 The chromosomes are not arranged around the periphery of the 



