GOLGl BODIES IN DYTISCUS 158 



merely division of the nucleus, and not of the cytoplasm. He 

 observed that binucleate and polynucleate cells were formed 

 as the result of amitotic nuclear division. During such division 

 the centrosome and archoplasm remained unchanged. The 

 archoplasm could be seen in the living cell, but not the centro- 

 some ; but the latter was to be seen in fixed preparations 

 stained with iron haematoxylin as two small black bodies 

 embedded in the archoplasm. Mitochondria were visible in 

 the living cells, but not the Golgi body. 



Mackhn's observations are of special interest in that they 

 substantiate materially the evidence that has been accumu- 

 lated against the view upheld by writers such as Meves (9), 

 that mitosis can occur in an amitotically-formed nucleus. 

 Binucleate cells were observed by Macklin to undergo mitosis, 

 but in this process the nuclei which had been formed by 

 amitotic division came together and their chromatin masses 

 fused to form the chromosomes which underwent the usual 

 stages of mitotic division. It is therefore concluded that 

 amitosis does not imply division of the cytoplasm but only 

 fission of the nucleus. 



3. The Golgi Body duking Amitosis in the Follicle 

 Cells of the Ovary of Dytiscus. 



In common with most insects Dytiscus has an ovary laterally 

 disposed on either side of the abdomen. Each ovary is com- 

 posed of a number of tubules containing a single row of oocytes 

 in all stages of -development, the most mature being at the 

 distal end. The oocytes are surrounded by the follicle cells, 

 and between each oocyte is a group of nurse or nutritive cells 

 whose function is to provide nourishment for the developing 

 oocytes. At the proximal end of the ovuliferous tubules is 

 a mass of undifferentiated cells from which arise three types 

 of cells, viz. oocytes, nutritive cells representing modified 

 oocytes, and the follicle cells in which the behaviour of the 

 Golgi body during amitosis was studied. 



It was found rather difficult to impregnate the body in the 

 follicle cells of insects. After a number of unsuccessful attempts 



