324 E. T. Bell, 



I have not succeeded in staining any granules in muscle with 



neutral red. In the kidney it is, however, easy to show a large number 



of neutral red granules. Free-hand sections were cut immediately after 



death and stained from a few minutes to one hour at 37° C in a 1 : 10000 



solution. But the number, size, and arrangement of the granules shows 



that they cannot to any considerable extent correspond to the lipo- Î 



somes. Some tubules, that contain only a few small liposomes, are j 



shown full of coarse granules by neutral red. A great many liposomes : 



are certainly not stained since they may be seen among the neutral red i 



granules. The neutral red picture is also variable. The granules often ' 



appear coarser after a long exposure than after a few minutes in the | 



stain. It may be that some liposomes are stained by neutral red ; but ; 



to assume that all neutral red granules are liposomes, as Cesa-Bianchi 



apparently does, is entirely unwarranted. Neutral red does not seem | 



to me to deserve a place among fat stains. I have not used methy- j 



lene blue. j 



Is 

 Effect of fixatives. It was stated in my preliminary paper (1910) 



that a large part of the Hposomes may be lost if the tissue be fixed ; 



first in formalin, alcohol, etc. Liposomes that stain intensely are only ] 



slightly affected as a rule by long exposure in formalin. The liposomes ! 



in the muscles of cats, and those of some dogs and frogs belong to this 



group. It is the weakly-staining, faintly-refractive liposomes that suffer j 



most readily. The more refractive a liposome is, and the more intensely j 



it stains, the greater is its resistance to formalin. A great many of ; 



the liposomes of ox muscle and also those of many rats, pups, etc., ; 



are lost after a few hours exposure in 10 per cent formalin, and every j 



liposome often disappears after two or three days in this solution. The \ 



liposomes of a sucking pup (fig. 10) nearly all disappeared after one day ,: 



in 10 per cent formalin. In some pups the liposomes are not much af- ^ 



fected. I 



In general the resistance of the liposomes to formalin may be | 



judged from the intensity of their staining with Herxheimer's solution, j 



The liposomes of a well-nourished cat stain intensely and are very I 



resistant to formalin; but those of a somewhat emaciated cat (fig. 5) j 



stain with only moderate intensity and are gradually removed by for- , 



I 



