1906.] Life-history of Adelea ovata, Aime Schneider 



157 



four microgametes, one of which is destined to fertilise the macrogamete ; 

 the remaining three perish. In the first nuclear division it was believed 

 that the quantity of chromatin was reduced, whereas the number of chromo- 

 somes was reduced in the second division. I am convinced that this is not 

 a correct interpretation of this particular gametogenesis ; and the inference 

 that the maturation of these gametes approaches the metazoan type is, to my 

 mind, quite unjustifiable. 



To follow the formation of the male gametes from the beginning, it is 

 necessary to describe in detail a merozoite of the male type. Such a 

 merozoite is shown in the accompanying figure (text-fig. 1). 



*%y£v 



■^ 



Fig. 1. 



It is seen to consist of a somewhat fusiform (or sometimes falciform) body, 

 containing a nucleus (n.) and a large peripheral karyosome (&.). Sometimes 

 two or even three karyosomes are present, but the usual number is one. 

 Occasionally it appears to be extranuclear. At one end of the merozoite — 

 usually that remote from the karyosome — a number of granules is usually, 

 though not always, present. These are the so-called " pigment granules " 

 (p. gr.). I am inclined to believe that they are really chromatin granules. 

 They staiu deeply with hematoxylin, and are coloured red by Giemsa's stain. 

 They are never present in macromerozoites. 



9. 10. H. 



Fig. 2. — Semi-diagrammatic Eepresentation of Formation of Microgametes. The 

 macrogametocyte is not shown. 





