Guilliermond - Atkinson 



204 



Cytoplasm 



B 



as ergastome. The terms cytosomes and cytome were first created 

 by P. A. Dangeard to replace those of spherosomes and spherome, 

 which were applied to the lipide granules in question here. 

 This writer, perceiving later that, as well as these granules, 

 there also exist chondriosomes, whose reality up to then he had 

 refused to admit, substituted the above terms for those of chondrio- 

 somes and chondriome and made the distinction, from that time on, 

 between the cytome corresponding to the chondriome and the ergas- 

 tome which includes all the lipide granules of a cell and for 



which he reserved the term lipo- 

 some. Here is the description 

 which he gives of them (1919) : 

 "The spherome is composed of all 

 the microsomes. The microsomes 

 are small, very refractive sphero- 

 somes of a fatty appearance which 

 blacken more or less with osmic 

 acid." P. A. Dangeard, contrary 

 to our judgment, maintained that 

 it is the microsomes, with the ele- 

 ments of the vacuome, which rep- 

 resent what the cytologists had 

 for a long time been calling 

 chondriosomes. At the present 

 time, Dangeard seems to have re- 

 nounced this opinion. KOZLOW- 

 SKI also confused these same 

 granules with the chondriosomes. 

 After observing only living mate- 

 rial, he maintained that plastids 

 arise by simple agglomeration of 

 these granules. 



Reserve lipides which are 

 found in many cells appear, in the 

 cytoplasm, like the microsom.es 

 which we have just been discuss- 

 ing but are present in much great- 

 er quantity. In endosperm cells 

 of the castor bean for example, at the period immediately preceding 

 the maturation of the seed, there are seen to form abruptly in the 

 cytoplasm, numerous small granules comparable to those 

 which normally exist in every cell and which present the same 

 histochemical characteristics. These finally fill the cytoplasm com- 

 pletely and then fuse into large lipide globules. In the cytoplasm 

 of some filaments of Saprolegnia, especially in the extremities of 

 the filaments which will form the zoosporangia, numerous granules 

 are also seen to appear which are comparable to the small 

 microsomes encountered in the other filaments. These fuse later 

 into larger globules which accumulate in the zoospores and serve 

 as reserves. 



D 



Fig. 141. — Endomyces Magnusii. A-C, 

 Regaud's method; D, Meves' method; 

 stained with haematoxylin. C, Ch, chon- 

 drioconts; Gr, lipide granules, brown 

 with osmium; N, nucleus, sufficiently de- 

 stained in A and C to show structure. 



