22 



MORPHOLOGY 







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there are certain other cells which are set aside for the purpose 

 of reproduction. These cells are called gonidia or conidia 

 (Figs. 1 6 and 17). There is, therefore, a division of labor or 

 a differentiation in function among the cells 

 of a filament in this group. 



The most highly organized group of the 

 higher bacteria is represented in Strep- 

 tothrix actinomyces, a form under the 

 Chlamydobacteriacese (see Fig. 17, A). 

 In the actinomyces the filaments do not 

 appear ordinarily to be composed of sepa- 

 rate individuals. Occasionally, however, 

 the protoplasm breaks up into rods similar 

 to bacilli. There is true branching similar 

 to that in the mycelium of a fungus (Fig. 



FIG. 16. Cladothrix 



hyaiina. Showing 18). The filaments often produce small 



gonidia formation. JT,J- / -j-\ ! i_ 



After Schmidt and round bodies (gonidia), which in turn pro- 

 Weis ' duce new individuals. There is often 



a club-shaped swelling on the end of a filament. In all 

 probability this is a degeneration product and not an organ of 

 reproduction, as was formerly thought by some writers. These 

 round bodies are not similar to spores, as is shown by the 

 staining reaction and power of resistance. It has been sug- 

 gested that the members of the actinomyces group constitute 

 a connecting link between the lower bacteria, on the one hand, 

 since the filaments occasionally break up into bacilli-like rods, 

 and the fungi on the other, since branching similar to that in 

 the mycelium of a fungus occurs. 



