242 R. R. HUMPHREY 



stainable with fuchsin, they do not hold their stain so tenaciously 

 as do these granules. The latter, though more easily preserved 

 than mitochondria, are similarly destroyed by fixation in alcohols, 

 or Bouin's fluid (picro-aceto-formol), and poorly preserved in 

 Zenker's fluid with the usual percentage of acetic acid. They 

 may be demonstrated excellently by Regaud's fixation and subse- 

 quent staining by the Weigert method. With this technique, 

 they are much more resistant to differentiation than are the mito- 

 chondria in adjacent spermatogonia of the same section, remain- 

 ing a deep black after treatment with the borax-ferricyanide 

 differentiator has rendered the mitochondria colorless. The mito- 

 chondria of the germ cells are, similarly, not well demonstrated 

 in Bensley preparations in which these granules are excellently 

 preserved and intensely stained. The suggestion is strong that 

 they differ sensibly from mitochondria, presumably by having 

 a larger proportion of lipoid in their make-up. 



It is found after osmic-acid fixers that the granules do not 

 usually blacken as do the larger lipoid droplets. They are more 

 perfectly preserved than the latter by such fixers as Regaud's or 

 the modified Zenker's. This less perfect preservation of the 

 larger droplets may, indeed, be ascribed to their greater size 

 and fluidity; the failure of the granules, however, to blacken with 

 osmic acid suggests some chemical difference as well and the 

 greater activity of their substance in reducing dichromates bears 

 out this suggestion. The greater solubility of the larger lipoid 

 droplets is apparent after osmic-acid fixation (Bensley 's). In 

 stained preparations mounted with cover-glasses the blackened 

 droplets may be entirely dissolved while the fuchsinophile gran- 

 ules appear undiminished in numbers. 



That the fuchsinophile granules arise from the smaller mito- 

 chondria might be inferred, since they appear gradually in cells in 

 wTiich mitochondria are already present, and upon first appearance 

 are of much smaller size than they subsequently become. Later, 

 too, when they are maximal in number as in figures 29 and 30, 

 sizes intermediate between the largest granules and the mito- 

 chondria may be distinguished. Other than this, I have secured 

 no evidence of their mitochondrial origin. The granules of inter- 



