438 INFECTIVE DISEASES. 



of the thread. It is difficult to say what further changes occur in 

 the ckib-shaped bodies ; in all probability they represent organs of 

 fructification. If so, the protoplasm in the interior of the club may 

 possibly undergo changes leading to the development of spores, 

 which are ultimately set free ; in some cases the terminal segment 

 of a club is separated by transverse fission in the form of a globular 

 body, a process resembling the formation of spores by abjunction. 

 In others, the forms sprouting from the club are suggestive of 

 teleutospores. There are occasionally long, slender forms, very 

 different from the ordinary clubs ; they possibly represent paraphyses 

 or abortive elements. In whatever way they may be formed, there 

 can be little doubt that spores are set free in the vicinity of 

 a rosette, and give rise to fresh individuals ; the ultimate result 

 recalling, as has been suggested, the appearance of " fairy rings." 

 There can be little doubt that spores and young fungi are taken 

 up by wandering cells, and conveyed to a distance from the parent 

 fungus, and thus fresh centres of growth are established. 



Appewrances of cultwres. — Bostrom, Wolff, Israel, Paltauf, and 

 others have shown that actinomyces can be cultivated in the 

 ordinary nutrient media. More recently the author has carried on 

 a series of cultivations for some years on glycerine agar, gelatine 

 and mUk, broth, bread-paste, and potato, in order to observe the 

 changes which take place, and to study the variations which he 

 found in the appearance of sub-cultures. The actinomyces after a 

 few days on glycerine agar at the temperature of the blood forms 

 little, white, shining, moist colonies, which may remain stationary, or 

 increase and coalesce. In a week or ten days, sometimes earlier, and 

 sometimes after several weeks, the cultures turn a bright yellow colour, 

 but some remain, though white ; others, again, have a tinge of pink, 

 and others are yellowish-brown (Plate XIX). After a time, a powdery 

 efiJorescence makes its appearance on the surface of the culture, 

 which may be either yellow or white in colour. The culture may go 

 on increasing, spreading over the surface of the medium, and retain 

 its yellow colour, or it may turn black in parts or completely so, 

 while the agar is coloured brownish-black. Cultures have a peculiar 

 sour smell ; the variations in cultures were all proved, by careful 

 testing by sub-cultures, to be due to the growth of the actinomyces 

 under varying conditions of soil, temperature, and the supply of air. 

 The stage of efflorescence corresponds with the breaking up of the 

 filaments into masses of cocci, and chains often closely resembling 

 streptococci. Gelatine is slowly liquefied. 



Wolff and Israel cultivated actinomyces on raw and boUed 



