BACIERIA GREGARINIDvE. 



207 



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

 into chromogenous (pigment), zymogenous (fermentation), and pathogenous 

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

 vegetate in the Zoogloeaform, e:;/.. M. prodigiosus Ehbrg. in potatoes, etc., 

 To the Zymogenous belong M. uretc. urine ferment ; to the Pathogenous 

 M. nii-rlnif. the Pox Bacteria, M. xepticux of py;emia, M. dlplithcricHS of 

 diphtheritis. 



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

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

 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. Lineula 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 Hoffman. 



Of the Filiform Bacteria 

 the motile Bacillus (vibrio) 

 Kiibtilix Ehrbg. occasions 

 butyric acid fermentation, 

 but is also found in infusions 

 together with B. term a. 

 Very nearly allied and 

 hardly to be distinguished 

 is the motionless Bacillux 

 (inthracis of inflammation 

 of the spleen. Vibrio ruaula 

 and si'rpeit* are charac- 

 terised by constant undula- 

 tions of the chain. Finally 

 these lead to the spiral 

 forms of which Spirocluct<i' 

 resembles a long and flexi- 

 ble but closely wound, and 

 Spirillum, a thick, short, 

 and coarse screw. Spiril- 

 lum tcnax, undula, volutans, 

 the last with a flagellum at 

 each end. 



2. The Greyarinidte * are 

 unicellular organisms which 

 live 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 (sometimes with a subcuticular 

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



* N. Lieberkiihn. " Evolution des Gregarines," Mem four. de VAeud. de Belij. 

 1855. N. Lieberkiihn, " Beitrag zur Kenntniss der Gregarincn." Arch, fur 

 Anat. und Pliyxlul.. 1865. E van Beneden, ' Recherches sur 1'evolutiou des 

 Grdgarines." Bulletin de VAcad. roy. dc -Bclyitjne, 2 Scr. xxxi.. 1871. Ainu'' 

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

 et de Roscoff." Arch, dc Zod. Experiment. , Tom IV., 1875. 



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

 lorhynchus oliff acanthus out of the intestine ofCallopteryx. 

 b, Gregarina (Clepsidrina) polymorpha from intestine of 

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

 process of eucystmeiit. d, Encysted Gregarina. e, 

 Stage of formation of Pseudonavicella?. f, Pseudo- 

 navicellacyst with ripe Pseudonavicella;. 



