GIANT-CELLS OF BONE-MARROW 129 



Both the conclusion of an identity of these elements and that 

 of a dissimilarity have had numerous supporters. Perroncito 

 ('10), Cajal ('14), and Gatenby ('19), for example, regard these 

 elements as genetically distinct structures; Deineke ('14) and 

 Monti ('15), among others, regard them as only different mor- 

 phologic expressions of the same substance. Duesberg ('20) 

 originally regarded the two elements as different structures. 

 In his latest consideration of this question, he seems unwilling 

 to state a definite conclusion, while apparently inclining to a 

 belief in a close genetic relationship. 



When one recalls the illustrations (figs. 5 and 9) of the Lewises 

 ('15) showing the granular mitochondria of connective-tissue 

 cells in tissue cultures fusing to form bacillary and filar mito- 

 chondria, which latter anastomose to form a comphcated net- 

 work, one sees a series of events which has been actually observed 

 in living cells paralleling in a measure the steps that would most 

 conceivably be taken by mitochondria in the process of trans- 

 formation into a Golgi apparatus. 



We know as yet too little definitely about the chemistry of the 

 Golgi apparatus, and of the chemically different substances and 

 mixtures which may give an identical color reaction with osmic 

 acid, to warrant anything approaching a final statement with 

 regard to the genetic relationship between the mitochondria and 

 the Golgi apparatus. In this material, considering the practically 

 innumerable granules in the cytoplasm, and the localized dis- 

 tribution and the relatively small size of the Golgi apparatus, 

 we are on safe ground when we interpret the granules of the giant- 

 cell cytoplasm as mitochondria, rather than as portion of a diffuse 

 Golgi apparatus. 



As regards the physical constitution of the Golgi apparatus, 

 Pappenheimer ('16) inclines to accept the conclusion of Cajal 

 that the apparatus consists of a system of canaliculi which are 

 filled with a lipoid-containing substance. The canals are thought 

 to be relatively rigid and of permanent form in certain fixed 

 cells, but more plastic in secretory and embryonic cells (p. 138). 

 Duesberg ('20) expresses some skepticism regarding such an 

 interpretation (p. 76). Bensley ('14) interprets the apparatus 



