Chapter VII —65— The GhondrJome 



chondrioconts. In whatever form they take, the chondriosomes 

 appear as elements of very little refractivity, being only slightly 

 more refractive than the cytoplasm. They are, however, always 

 visible but are more or less clearly singled out depending upon the 

 viscosity and density of the cytoplasm. Their visibility is sufficient 

 for a satisfactory motion picture to have been made of them (GuiL- 

 LiERMOND, Obaton and Gautheret). 



The chondriosomes are slowly moved about by the c5d:oplasmic 

 currents. Their very irregular and ordinarily extremely slow dis- 

 placement may accelerate or stop brusquely and then begin again. 

 In the course of their movements, the mitochondria generally keep 

 their shapes but the chondrioconts modify theirs constantly. We 

 have been able to follow the same chondriocont during a half hour 

 (Fig. 70) and to draw all the variations in form which it under- 

 goes. When the chondriosomes are not moving, they are usually 

 rectilinear. During their movements, however, they may assume 

 the most diversely sinuous forms, appearing as S, Z, propeller- 

 shaped, etc. Their movements are reminiscent of Spirochaetes. 

 Often the chondrioconts meet, become entangled, then separate, but 

 we have never observed anastomosis, although they frequently 

 branch. Their ramifications which are, moreover, transitory, are 

 brought about by changes in shape necessitated by obstacles en- 

 countered by the chondrioconts along their path. Thus when a 

 chondriocont suddenly encounters a lipide granule, the chondrio- 

 cont branches and goes around it. The same effect can be produced 

 by currents moving in a direction opposite to that of the chondrio- 

 cont. This transitory branching, comparable to a sort of pseudo- 

 podium, shows that chondrioconts are made up of a semi-fluid and 

 very plastic substance. They are capable of becoming shorter by 

 thickening, or of increasing in length by growing thinner. They 

 sometimes appear spindle-shaped or even show on their long axes 

 small, sometimes vesiculate, swellings which afterwards disappear. 

 These variations in form have been compared to amoeboid move- 

 ments and there has been an attempt to explain them as due to 

 modifications of surface tension (Milovidov). 



Under the ultramicroscope, the chondriosomes are usually in- 

 visible or just barely visible but in a few cases they may be dis- 

 tinguished very clearly by their slightly luminous contours, espe- 

 cially in very large hyphae where the cytoplasm forms only a thin 

 layer about the vacuole. The chondriosomes are optically empty 

 like the cytoplasm and seem to behave as a hydrogel. It may be 

 supposed that they constitute a coacervate system in the cytoplasm, 

 since they are not miscible with it. They can also be made to 

 appear with a color different from that of the cytoplasm by the 

 Zeiss micropolychromar. (Fig. 29). 



The chondriosomes of the Saprolegniaceae behave as extremely 

 fragile elements and, as Faure-Fremiet observed for animal cells, 

 the least disturbance in the osmotic equilibrium of the cell, such 

 as a too hypotonic medium or the slightest pressure on the cover 

 glass of the preparation, suffices to alter them. Alteration, i.e., 



