Si'UDrivS OF REPRODUCTIVE ELEMENTS: II. 



3i>5 



or less homogeneous :nid"ti-;insp:ireüt, and is not so distinofly to be 

 seen as the archo|)l;isiii. Ihit treated with reagents, the chromosomes 

 come into view distiiictlv. 



5) Knch chromosome consists of a row of disc-shaped microsomes 

 irregularly scattered in the nucle<jplas]n. The number of the chromo- 

 somes is not clenr. but in most cnses has been counted to lie ten. 



6) The chromatin substance of each of the microsome discs 

 collects at the {>erij)hery and forms a microsome-i'in"". 



7) In the nucleus of a dividing animal, each microsome-ring 

 splits into h;df-rings thus dividing a chromosome in halves, while 

 in that of the spore-forming animal two successive divisions of a, 

 microsome-ring take place, so that a single chromosome is directly 

 divided into four daughter ones. 



8) The clu-omosomes collect on that side of the nucleus which is 

 nearest to the archoplasm, and spread out towards the other j)ole. 

 The pole where the archoplasm lies thus corresponds to Rabrs Folfeld 

 and the other pole to his Gengenpol. 



9) The archoplasm divides and forms a very large spindle which 

 lirst lies tangential to the surface of the nucleus. This division of the 

 archoplasm is succeeded by the separation of the chromosomes into 

 two groups each attracted (?) by its respective archo])lasm. 



10) The archoplasmic spindle thus formed pushes-in the nuclear 

 wall on which it lies, and the nucleus assumes in consequence a half- 

 ring form. 



11) lîy the separation of the archoplasms, a sj)indle is produced 

 wliicli in all essential characters appears like the form known as the 

 " disaster stage," with a large archoplasnn'c mass at each end of the 

 spindle. 



12) The fibres of this spindle are therefore continuous from one 

 pole to the other and lying outside the nuclear wall become in no way 



