gametoCtBNEsis of saccocirrus 35 



or spermatid were often remarkably different in size and 

 number from those in another example. It is thus clear that 

 the mitochondria are not usually of markedly definite number 

 or size in the germ-cells or somatic cells of any given species. 

 With reference to the Golgi apparatus the same applies. In 

 Helix a s p e r s a (9) and in other Molluscs it was shown that 

 the dictyosomes or Golgi batonnets could vary in number 

 considerably. 



Moreover, examination of preparations of this apparatus 

 in any somatic cells, as well as germ-cells, gives the impression 

 that the Golgi elements are variable to an extreme. 



The statement — ' In ordinary cell-division each chromosome 

 is halved ' — may now be used as a basis for comparison and 

 contrast with what occurs in the mitochondria and Golgi 

 apparatus. In many cases it is difficult to get quite complete 

 evidence as to whether a mitochondrium does divide during 

 cell-division, but the general impression one gathers after 

 examining cells in division is that the mitochondria are sorted 

 out whole and haphazardly. In special cases, e. g. Centrurus 

 (30) and Paludina, it is possible that the elongate mitochondria 

 are halved transversely but not longitudinally. In by far the 

 majority of animals it seems tolerably clear that the process 

 of chondriokinesis or distribution of the mitochondria (or 

 chondriosomes) between the daughter-cells is haphazard, 

 and not in any way comparable to the process of karyokinesis. 

 This result has been arrived at by a number of independent 

 workers, and may be taken as established. 



The Golgi body in the dividing cell consists of rods or granules 

 (dictyosomes) ; in most cases these dictyosomes keep around 

 the zone of the amphiaster, often stuck on the asters them- 

 selves, and, as with the mitochondria, the observer is impressed 

 with the fact that the whole train of events in dictyokinesis, 

 or the distribution of the dictyosomes between the daughter- 

 cells, is extremely haphazard and much less precise than 

 with the process of karyokinesis. That this is so can easily be 

 shown to be the case in the molluscan germ-cell ; in the sper- 

 matid of Limax maxim us the Golgi apparatus generally 



D 2 



