very fine fibres is seen. These are the prolonged rays of 

 the asters, and they form the nuclear spindle which con- 

 verges towards the poles and diverges about its equator. 

 The chromosomes are now ranged in a ring (the equatorial 

 pla^e), lying flat around the equator, and this completes 

 the first stage of division, the Prophase. 



Then the chromosomes split longitudinally, and the two 

 sets of halves draw apart towards the poles. That is the 

 second stage, the Metaphase. It is succeeded by the Ana- 

 phase, a brief period occupied by the chromosomes passing 

 to their respective poles where they undergo regressive 

 changes, repeating the prophase processes in the reverse 

 order, and becoming normal resting nuclei. Finally the 

 original cell is constricted about the middle (the Telophase 

 stage) and thus two are formed, each containing a daughter 

 nucleus. 



The whole process evidently ensures equal division 

 (quality and quantity) of the chromatin of the original 

 nucleus between the two resulting nuclei. 





 What are Germ Cells ? 



In certain Protozoa (e.g., Volvox) and in all Metazoa 

 (many-celled animals) the body is composed of two dis- 

 tinct kinds of cells (1) those which are concerned with 

 the general metabolism but which are incapable of con- 

 jugation or syngamy, namely, the somatic or body cells ; 

 and (2) those which, retaining the inherent qualities of 'the 

 individual, function solely as reproductive, namely, the 

 germ cells^\ In the .Protozoa the germ cells -arise by pro- 

 cess of fission and breaking up of the individual (e.g., 

 Coccidiidce and certain Hcemoflagellates), or 'of certain 

 individuals of a colony (e.g., Volvox). In Hydra they are 

 developed from special ^tftrfitltfJP 1 pfi1lH r and in Sponges 

 from some of the amcebocytes. 



In higher animals they arise from that thickened part 

 of the epithelial lining of the coelome known as the gfir- 

 niin&l epithelium. These primitive germ cells grow larger 

 than their ordinary epithelial neighbours ; they multiply 

 by repeated division, accumulate reserve material, and 



