HISTORY OF MITOCHONDRIAL RESEARCH 17 



dria. In the first sentence the word 'supposed' gives a 

 clue to the finahty of the evidence. 



(3) Artificial mitochondria have been made by Lowschin of 

 lecithin in different salt and albumin solutions (resulting in the 

 formation of lecithalbumin), which apparently present the same 

 form and solubiUties as true mitochondria. They form granules, 

 rods, and filaments which, he claims, multiply by division. He 

 embedded them in glycerin-gelatin, fixed them, and found that 

 they stained in the usual way by the various mitochondrial 

 methods. 



The production of rod-like, coccoid, and variously-shaped 

 "precipitation bodies" in solutions is a common phenomenon 

 in colloidal chemistry, and has been obtained in various ways 

 with different kinds of reagents. Certainly this is not a 

 phenomenon limited to solutions containing a phospholipin- 

 albumin complex. 



(4) The temperature solubihty of mitochondria may also be 

 significant. It has been discovered by PoUcard (1912d, p. 229) 

 in the case of animal tissues, and by N. H. Cowdry (1917, p. 220) 

 in plants, that the mitochondria are soluble at a temperature from 

 48° to 50°C., while the other parts of the cell remain practically 

 unaffected. Phosphatids have a low melting-point also. 



Because mitochondria disappear at a temperature of 48° 

 to 50°C., and the melting point of phosphatids is also low, 

 does not necessarily imply that the two are identical in 

 constitution. In some experiments that the author (Wallin, 

 '22a) made on the effects of temperature on various bacteria, 

 it was found that some strains of bacteria "dissolved" at 

 this temperature. 



(5) Apparently the specific gravity of mitochondria is somewhat 

 greater than protoplasm (Faure-Fremiet, 1913, p. 602). This is 

 determined by the centrifuge method. If they are thrown down 

 they are said to be of high specific gravity. If the protoplasm is 



