them what you will" are formed from special polar cells. "If 

 the formation of the small embryos from these 'polar cells' is 

 confirmed, then it will be an important increase of our expanded 

 knowledge about the process of animal development" (p. 10). 23 



Later Baer reported in detail the investigations of 

 M. S. Ganin, ^4 prosector at Kharkov University. His 

 observations are "extremely careful and circumspect, repre- 

 senting great interest." Describing in detail the structure 

 of larvae, Ganin turned to their embryonic development; more- 

 over, he reached the conclusion that the development of the 

 young larvae inside the older ones did not arise from the fat 

 body. He found an ovary, in which ova developed, giving the 

 beginning to the young generation. Ganin thought that the ova 

 of viviparous diptera that he investigated are differentiated 

 from the ova of those insects which are characterized in the 

 imaginal stage by the absence of the nucleus (Purkinje's 

 vesicle) (117). Leuckart soon confirmed Ganin's observations 

 concerning the development of Miastor ova within special organs, 

 but he called these organs small embryos and not ovaries as 

 Ganin called them. The developing group of cells in these 

 small embryos are separated and fall in the body cavity. In 

 each of these groups one cell increases in size and serves for 

 the formation of the embryo, while the others, as in the 

 embryonic chambers of other insects, play the role of feeding 

 cells. 



Baer considered it correct to distinguish the embryos 

 identical with ova which are developed from ovaries produc- 

 ing true ova, and approved Leuckart 's suggestion of calling 

 the early embryos of the Miastor false ova (PSEUDOVA) (118). 



23. In the following year Mechnikov published detailed reports 

 on the embryonic development of Miastor ("Uber die 

 Entwickelung der viviparen Cecidomyidenlarve, nebst 

 Bemerkungen iiber den Bau und die Fortpflanzung derselben," 

 ibid . (1866) , 16, p. 407). In this paper the development 

 of small embryos from polar cells was traced in detail . 



24. M. Ganin, "Neue Beobachtungen liber die Fortpflanzung der 

 viviparen Dipterenlarven," ibid . (1865), 15, p. 375; 

 ZAP I SKI IMP. ACADEMII NAUK, 1865, 8, pp. 36-56. 



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