EACTEEIA GREGA.HIUTDJE. 



207 



They can only be divided, according to their various methods of development, 

 i7ito chromogenous (pigment), zymogcnous (fermentation), and pathogenous 

 (contagion) divisions. The first appear in coloured gelatinous masses and 

 vegetate in the Zoogloeaform, e.g.. M. prodigww* Ehbrg. in potatoes, etc. 

 To the Zymogenous belong M. urea, urine ferment ; to the Pathogenous 

 J/. vaccinat, the Pox Bacteria, Jf. septicus of pyaemia, M. dijpktkcri&t* of 

 diphtheritis. 



The Rod Bacteria form small chains or threads, and exhibit spontaneous 

 motions, especially in the presence of abundant nourishment and oxyges. 

 Here belongs Bacterium termo Ehrbg. distributed in all animal and vegetable 

 infusions and the necessary ferment in putrefaction, just as yeast is in alcohol 

 fermentation ; also B. Lineola Ehrbg. of considerable size, which exists in spring 

 water and in standing water, in which there are no products of putrefaction, 

 and, as well as the former, has a zoogloea jelly. Another Bacterium form acts 

 as ferment of lactic acid, 

 according to Hoffmann. 



Of the Filiform Bacteria 

 the motile Bacillus (vibrio) 

 subtilis Ehrbg. occasions 

 butyric acid fermentation, 

 but is also found in infusions 

 together with B. tcrmo. 

 Very nearly allied and 

 hardly to be distinguished 

 is the motionless Bacillus 

 anthracis of inflammation 

 of the spleen. Vibrio ruqula 

 and scrpens are charac- 

 terised by constant undula- 

 tions of the chain. Finally 

 these lead to the spiral 

 forms of which Spirocha&a 

 resembles a long and flexi- 

 ble but closely wound, and 

 fy trillion, a thick, short, 

 and coarse screw. Sj) tril- 

 lion tcnax, 'undula. volutans, 

 the last with a flagellum at 

 each end. 



2. The Grcgarinido} * are 



FIG. 149. Greyarlna (after Stein and Kolliker). a, Sty- 

 lorhynchus oUgacanthus out of the intestine otCallopteryx. 

 b, Gregarina (Clepidrina) poJymorpfia from intestine of 

 the meal beetle, during conjugation, c, The same in 

 process of encystment. d, Encysted Gregarina. e, 

 Stage of formation of Pseudonavicellro. /', Pseudo- 

 navicellacyst with ripe Pseudonavicellaj. 



unicellular organisms which 

 lire as parasites in the 

 intestine, and in the internal organs of the lower animals. The body is fre- 

 quently elongated like that of a worm, and consists of a granular viscid central 

 mass surrounded by a delicate external membrane (st metimes with a subcuticular 

 layer of muscle stripes). The nucleus, a round or oval clear body, is embedded in 



* N. Lieberkiihn, {< Evolution des Gregarines," Mem com: de VAcad. de Belf). 

 1855. N. Lieberkiihn, " Beitrag zur Kcnntniss der Gregarinen." Arclt. fur 

 Anat. mid PhyxioL, 18G5. E van B.cnedcn, "Becherfehea sur 1'evolution des 

 Gregarines." Bulletin de VAcad. roy. de Bt'h/iyiw, 2 Ser. xxxi., 1871. Aime 

 Schneider, " Contributions a 1'histoire des GrOgarines des Invertebres de Paris 

 et dc Koscoff." Arch, dc Zool. Experiment.. Tom IV., 1875. 



