CHEMICAL NATURE OF CERTAIN GRANULES 69 



general rule that these cells, aside from any other function that 

 may be ascribed to them, serve as a storehouse for fatty material. 



Finally, one may ask if these observations throw any light 

 upon the histological nature of the granules. Are they derived 

 from the chromatin of the nucleus, i.e., are they chromidial in 

 nature? In favor of a nuclear origin is the fact that while the 

 majority of the granules lie in the peripheral portion of the cell, 

 it is common to find some in the neighborhood of the nucleus; in 

 fact, they may be found lying against the nuclear membrane. 

 Moreover, with most staining methods the granules and the chro- 

 matin are stained by the same dye. Such observations are, of 

 course, merely suggestive. On the other hand, when the granules 

 and the chromatin were given an equal opportunity at an acid 

 and a basic dye without any more differentiation than was 

 obtained by washing with distilled water, the chromatin took 

 the basic, while the granules preferred the acid dye (fig. 2). So 

 that, if one assumed that the granules are derived from the 

 nucleus, he would also have to assume that they undergo a change 

 in chemical nature as soon as they escape from the nucleus. Some- 

 what more direct seems the evidence in favor of their derivation 

 from the cytomicrosomes — Altmann's granules, mitochondria, 

 or whatever name shall be given to the small granules located in 

 the trabeculae of the spongioplasm. As we have seen, it is quite 

 possible to stain these at the same time with the granules. Appar- 

 ently all that is needed to convert them into the granules is the 

 incorporation of fatty material and increase in size; there would 

 thus be produced the picture of granules lying in small vacuoles 

 of the spongioplasm. 



Another question which presents itself is, are these granules 

 mitochondria? If Benda's dictum is correct, that his staining 

 method for mitochondria is specific and that all cytoplasmic 

 structures which stain by this method are mitochondria, then 

 these granules are undoubtedly mitochondria. It may be pointed 

 out further that Faure-Fremiet,^ Regaud and others have pre- 

 sented evidence — evidence based for the most part upon deduc- 



8 Faure-Fremiet, Mayer et Shaeffer. Sur la microchemie des corps gras. 

 Arch. d'Anat. Microsc, T. 12, 1910. 



