248 GREGOR T. POPA. 



substance not influenced by acids, essentially lipoproteins (pro- 

 teins united with lipoids) and lipoids. If this is true, the stains 

 characteristic for proteins, such as methylen blue, will stain no 

 more, and on the contrary, the stains of the fuchsin series still 

 will give a coloration. 



This method was used by Schumacher in studying leucocytes, 

 yeast cells, liver, lung, and skin. I have applied this method 

 in studying the spermatozoa. 



With the above method one obtains with Victoria blue the 

 following pictures (Fig. 8) ; staining with methylene blue fails 

 completely. This demonstrates that the various portions of 

 spermatozoa stained with Victoria blue by the procedures 

 already described, resist the action of strong acids, while the 

 other portions are destroyed. Therefore, according to the theory 

 of Schumacher, we can say that in the construction of the tail, 

 middle piece, and acrosome of the spermatozoon there is a great 

 quantity of lipoid substance. 



B. 



For deciding if in an organic construction, which resists the 

 action of acids and still is stained by Victoria blue, there are 

 free lipoids or lipoids associated with proteins (lipoproteins), 

 Schumacher uses another procedure: Smears made as in A 

 (above) are placed for 24-36 hours into a mixture of alcohol and 

 ether. Afterwards the slides are transferred for 24 hours to 

 HC1 i : 4. The staining following is identical with that de- 

 scribed in A (above). 



The idea is this: The alcohol-ether dissolves and washes out 

 free lipoids, but does not touch the lipoproteids; afterwards HC1 

 destroys the proteins, and again the lipoproteids remain intact, 

 and thus they are isolated. If, after such a treatment, we still 

 obtain a coloration, we can say that there is a lipoprotein 

 component. 



Applied to the study of spermatozoa, this method gives the 

 pictures shown in Fig. 9. A pale reticulum built by interlacing 

 tails, and here and there some knobs at the ends of fibers, inferred 

 to be the remains of middle pieces. It is to be noticed also that 

 the fresh preparations immediately after staining with Victoria 



