140 CYTOPLASMIC INCLUSIONS 



difficulties. The individual cells are either separate or in such small 

 aggregates that all cells and all parts within the cell are exposed to 

 essentially the same concentration of reagents. The variations in the 

 stage of the Golgi granules can be observed directly in living Protozoa, 

 so that the impregnation of the granules can be compared at equivalent 

 stages, which can be identified with or without impregnation. In meta- 

 2oan cells the Golgi nets are extremely difficult to demonstrate in the 

 normal living cell, so that it is at present impossible in these cells to 

 check the structures independently of impregnation. When standard 

 conditions are achieved both around the cell and within the cell, abso- 

 lutely consistent results are attained, even with osmic acid (MacLennan, 

 1940). Under these conditions, 100 percent of the digestive granules, 

 fatty acid granules, excretory granules, and so forth, impregnate, with 

 the result that these types cannot be separated on the basis of the Golgi- 

 type reactions. The results of Hall and Nigrelli (1937), which seem 

 to show that excretory granules and digestive granules are erratic in 

 impregnation, is due to failure to allow for changes in composition and 

 aggregation or for the occasional lack of these granules at certain times 

 in the life cycle. All the stages have been lumped together, rather than 

 equivalent stages compared. 



In view of the fact that osmic acid is reduced by many different sub- 

 stances, it is highly important to prove that the impregnated bodies 

 are not some other component (Hirschler, 1927; Bowen, 1928). Re- 

 sistance to bleaching by turpentine or hydrogen peroxide is more pro- 

 nounced in Golgi bodies than in most mitochondria, but unfortunately, 

 even with this method, there are too many border-line cases in which 

 the individual judgment of the observer is the determining factor. 

 However, this individual judgment can be eliminated in comparing 

 Golgi bodies and mitochondria by the use of such methods as the Alt- 

 mann aniline acid fuchsin stain after osmic impregnation. Such a com- 

 parison of Golgi bodies and segregation granules is not possible, since 

 the major criteria of the one is a fixation method and of the other 

 is a vital staining method. If the two components have a different 

 distribution, a comparison of different cells is sufficient to establish the 

 difference (MacLennan, 1933), but too often there is in both cases 

 merely a random distribution. The most famous case of this sort is that 

 of the gregarines, in which Joyet-Lavergne (1926b) described the Golgi 



