Chapter IX 



91 — Chondriosomes & Plastids 



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elements which are different, but whose form is similar: the plas- 

 tids, peculiar to chlorophyll-bearing plant cells ; and other elements, 

 which, hesitating for some unknown reason to liken to the chon- 

 driosomes of animal cells, he groups into a category which he calls 

 the pseudo-chondriome, 



Weier (1930-1933), having obtained impregnation of the chlo- 

 roplasts of Polytrichum commune by Golgi technique, felt justified 

 in likening the plastids of plant cells to the Golgi apparatus de- 

 scribed in animal cells. This theory was adopted by DuBOSCQ and 

 Grasse who, in a recent treatise, maintain that in animal cells 

 there are two sorts of permanent, closely allied constituents of a 

 lipoprotein nature, namely, the chondriosomes and the Golgi mate- 

 rial, or dictyosomes, the latter being comparable to the plastids of 

 chlorophyll-bearing plants. 



Finally, Kiyohara (1936), after mak- 

 ing observations of living material car- 

 ried out under improper conditions, 

 thought he noticed that all the plastids 

 normally appear as vesicles and that it 

 is the mitochondrial technique which al- 

 ters them and makes them appear as 

 chondrioconts. But this Japanese inves- 

 tigator obtained plastids of vesicular 

 form by osmic impregnation, the tech- 

 nique used fot- the detection of the Golgi 

 apparatus. He thinks that chondrio- 

 somes do not exist in plant cells and that 

 all forms described under that name cor- 

 respond to images brought about by 

 alterations in the plastids. He reports, 

 however, that in mature cells there al- 

 ways exist, as well as the large vesicular 

 plastids, other much smaller vesicles, 

 but these he believes to be plastids in the 

 act of degenerating. 



All these theories, aside from being essentially contradictory 

 are, unfortunately, at variance with the facts. They are the result 

 of hasty generalizations, founded on observations limited to certain 

 types of cells and carried out, most often, with defective techniques. 

 They give evidence of an insufficient knowledge of that which in 

 animal cells has been designated as chondriosomes and which have 

 been recognized in all the fungi. 



It is now demonstrated by our research that in mature cells 

 the plastids without chlorophyll generally keep the shape charac- 

 teristic of the chondriocont. For example, it is in this form that 

 they appear in the epidermal cells which we have already described 

 (Iris, tulip, Allium Cepa) . It is therefore impossible to attribute, 

 as do Meyer and Sapehin, the form of chondrioconts to division 

 figures of plastids which have for the moment stopped dividing. 

 It has also been proved in the most evident fashion, by our re- 



Fio. 59. — The chondriome. 1, 2, 

 Root of Cueurbita Pepo. 1, meri- 

 stem; 2, from differentiated cell of 

 parenchyma, some thicker chon- 

 drioconts (P) form starch, short 

 rods and mitochondria not per- 

 ceptibly changed; a few elongate 

 to thin chondrioconts. S, young 

 ascus of PtisttUaria veaievlosa. 

 4, frog's liver. 



