386 MARGARET R. LEWIS AND WARREN H. LEWIS 



Fat globules 



The connection between the mitochondria and the formation 

 of fat is a very complex and much discussed subject. It has 

 undoubtedly been shown that the mitochondria are bodies which 

 contain lipoid (Faure-Fremiet '09; Regaud and Mawas '09 

 Faure-Fremiet, Mayer, Schaeffer, '10; Regaud '10; Mawas '10 

 Mayer, Rathery, Schaeffer, '10; Duesberg '11; Dubreuil '13 

 Cowdry '14). Our experimental work shows that the mito- 

 chondria act in many ways like bodies which contain lipoid. 

 They are soluble in xylol, chloroform or ether, are slightly black- 

 ened by means of osmic acid, and in fixed preparations are stained 

 blue by means of nile blue B extra and yellow by means of Sudan 

 III. It seems probable that the bodies which contain lipoid 

 should form the fat globules, and many observers have tried 

 to establish this (Metzner '90, Zoja '91, Loyez '09, Russo '09, 

 Dubreuil '13). Others have claimed that the mitochondria are 

 indirectly connected with the formation of fat (Bluntschli '04, 

 Van der Stricht '05, Van Durme '07, Lams and Doorme '08, 

 Schoonjams '09). 



The masterly papers of Dubreuil ('11, '13) appear to show 

 clearly and concisely each step in the formation of fat droplets 

 from the mitochondria, and without doubt from the fixed mate- 

 rial which Dubreuil had at hand it seemed to be the logical con- 

 clusion that the fat is formed from the mitochondria. Guillier- 

 mond ('13) in a set of observations equally clear uses many 

 figures similar to those of Dubreuil, but reaches the conclusion 

 that the mitochondria form the glycogen granules of certain 

 cells. It is certainly evident from our observations that no defi- 

 nite conclusions can be drawn from the morphology of the mito- 

 chondria present in any one cell at any one time. Various 

 chemical tests and continued observation of a given mitochon- 

 drium are necessary to establish any morphological conclusion. 



In our fixed preparations (fig. 24 a) all the figures shown by 

 Dubreuil as evidence that the mitochondria form the fat can 

 be found, i.e., threads, loops, rings and fat droplets, but the 

 study of any one such mitochondrium in the living cell has 



