SUPERNUMERARY CH K< >M< >-< >M 1 - IN i I I 1 HOPI11L! S. 225 



unusual case of polarization, but here only nine polarized loops are 

 -ent and the other spireme thread- extended in various diiec- 

 tion- through the nucleus. In some follicles there is a perfectly 

 sharp divi-ion-line between cysts containing spermatocvte nuclei 

 of the chaiacter of that shown in Fic r . 2.^. and cysts in which the 

 -pin-mi- i- about twice as thick (Fig. 27). There is no evidence 

 of ti -I..-;., nap-is, and also no evidence of any such longitudinal 

 contraction of the threads as would be required to give tin- thicker 

 -pin-iii'- of I ig. 27. In other follicles there come in bet \\eeii 

 tli -, other cysts in which as a rule the- chromatin 



thn-.id- are \-ry irregularly distributed; i. e., thru- i- a con- 

 cpicnoii- ab-i-mv of the rather even spacing of tin- thn-ad- ol>- 

 -T\i-d in Figs 22 and 23. Careful inspection of -uch cysts 

 reveals varioi .'-sin pairing, conjugations, or -ynap-i- "I the 



chroiiMtin tlin-ads (Figs. 25 and 26). In tin- sunc cyst "tic 

 ofii n find- \arious stages, only one or two pair- and the other 

 thread- -iirJe as in Fig. 25, and all stages up to one in which 

 all ot the threads arc in pairs. Occasionally some of the pair- in 

 a inn leu- -how as much polarization as is indicated in I ig. J<>, 

 I'lit in the -ame nucleus other pairs are differently di-iril.ui. !. 

 I Inn i- in \ IT -uch complete polarization as i- sin >wn in ^ >m< . >t 

 tin tii'iin-- of ( ,n'i;oire Cio), the Schreiner- '"i 'n 



and oilu-i^. The occurrence of various stage- of p.u\i-\ nap-is 

 in the -.inn- cyst, the substantial agreement in -i/e of the chn.- 

 m.itin thn-.id- through the stages indicated in I -L-. 2; 2'>, and 

 the -pirenir of double size in the next stage, pn-elude the p" 

 bilit\ of iiiirrpreiing the paired condition seen in I i--. 25 and 2<> 

 as a longitudinal split. Homologous chronu in some way 



("in. together, anil gradually twist up into a tighter and ti^hii T 

 ro|u--like -Hand. A casual comparison of cysts in th' 

 sho\\ n in I i-. j; with the earlier stages (Figs. 2,^ to ji.i, u-ing low 

 po\\er- of the microscope, simply gives the impression that here 

 \\e ha\e a -pitvme, or sections of a -pireine, twice as thick a^ in 

 the |n-\ious stages, but study of such nuclei with /ei-- 1.5 nun. 

 and oc. 12 n-veals the double and twisted condition of the strands 



Ei Anaphasc showing segregation of homologous chromosomes and 



Ion.nitmlin.il splitting. 



1- 1.-. .^4-36. Second maturation initosis -howin^ diinnr|ihi-m in nunilx-r (18 

 and ii; 1 .tnd i-i|ii;U ional divisiiin. 



