Chapter VII 

 THE CHONDRIOME 



General conceptions. What is meant by chondriome in animal 

 cells:- As the chondriome was observed first in animal cells, it 

 seems necessary before beginning its study in plant cells, to recall 

 as briefly as possible what is understood under that heading in 

 animal cytology. 



The observations of Altmann cited in the previous chapter, 

 although exact, did not at first hold the interest of cytologists and 

 the bioplasts described by him were for a very long time confused 

 with the granules of Arnold brought out in most animal cells in 

 the time that followed by means of vital stains. It is known now 

 that these granules correspond to vacuoles and, in consequence, 

 have a quite different significance. It was believed that these 

 granules were merely artifacts and it was not until very much later 

 that the work of Benda, Meves, Regaud and Faure-Fremiet dem- 

 onstrated, by the use of special methods similar to those of Alt- 

 mann, the constant presence of small organelles in the cytoplasm 

 of animal cells. (Figs, 21, 22). They were somewhat similar in 

 shape and dimension to bacteria and were afterwards identified with 

 the bioplasts of Altmann and the fila of Flemming. These ele- 

 ments, whose width does not exceed 0.5-1^, were named chondrio- 

 somes by Benda (1906) and plastosomes by Meves. The general 

 term mitochondria is often applied to them. They appear now as 

 granules called mitochondria (Benda), now as rods or long, undu- 

 lating, sometimes branched filaments called chondrioconts. One of 

 these shapes may change into the other. The granule is capable of 

 elongating into a rod, then into a filament and this latter may, in 

 turn, fragment into granules. Mitochondria assembled in small 

 chains were called chondriomites by Meves. It was later recognized 

 that this very rare shape sometimes represents a transition form re- 

 sulting from a fragmentation of chondrioconts but more often still, 

 corresponds merely to an alteration of the chondrioconts caused by 

 the fixatives (Levi). Meves proposed the term c/ionc^nome (1908) 

 or plastome (1910) for the entire chondriosomal content of a single 

 cell. 



The chondriosomes are made up of lipoproteins, very rich in 

 lipides (phosphoaminolipides), and can not be brought into evi- 

 dence except by the use of special fixation techniques, called mito- 

 chondrial, which do not affect the phosphoaminolipides. Fixatives 

 containing alcohol or acetic acid, i.e., those which were most cur- 

 rently used before the discovery of chondriosomes, do not reveal 

 them. This explains why, although visible in living material, they 

 were able to pass unperceived for so long. Mitochondrial tech- 

 niques consist in fixing cells with a mixture of chromic and osmic 



