336 BOTANY I-AKT n 



toxins has been given. The following forms may be mentioned. ,s - /"y</<///..i-<'.v//> 

 j>!/iiif<"Hc$ (Fig. 257 a), the cocci of which form irregular or racemose masses, is 

 tin- most common cause of suppuration, while Xt irptwoccus pyogtncs (Fig. 257 b), 

 with cocci united in chains, occurs in erysipelas and other suppurative lesions. 

 .Mi'-rococcus (Z>t^A-<i<ri/N) <ii>norrJivrae (Figs. 257 c, 258 ), has somewhat flalti-n.-ii 

 cocci arranged in pairs, and causes gonorrhoea. Bacillus n nth rue I a (Figs. 257 d, 

 258 c) was found by R. KOCH in the blood and organs of animals suffering from 

 splenic fever. The relatively large rod-shaped cells may be united in short 

 chain* : they form endospores in cultures in the same way as the Hay bacillus. 

 Hurillus tetani (Fig. 257 e) occurs in the soil, and is the cause of tetanus. Its 

 straight rod-shaped cells arc ciliated, and grow only in the wound itself; their 



> 



\\* 





Fi<;. li.vs. stained i>vri>aiatioiui from Xie^k-r's Trj(-bovk <>j l'(<th^>njy. a, jjonococci hi the 

 jronorrha-al discharge, mucus and pus corpuscles with cocci (methylenc Mm- and eositi), x 700: 

 ft, tubercle bacilli in sputum of plitjiisis (fuclisin and mothylene blue), x 400; c, splenic fever 

 bacilli in the pustule of tlio disease (methylene blue and vesuvin) x 350. (From A. l-'is. in i:. 

 Vorlfs. "'"' />'"' '' r'V.) 



spores are formed in the swollen end. Bacillus injtucnzae, short, slender rods : 

 Bacillus -jifKds. small, stout, non-motile rods. LOFFLER'S Bacillus d iplit/n i-in, 

 (Fig. 257 /) consists of small rod-shaped cells sometimes thickened at one end. 

 KOCH'S Bacillus tuberculosis (Figs. 257 a, 258 b), which is found in all tuberculous 

 lesions and secretions, as in the sputum, is a slender, slightly curved rod. Typhoid 

 fever is caused by the ciliated cells of Bacillus typhi (Fig. 257 ft) ; Bacillus coli 

 (Fig. 257 i), the colon bacillus, which is as a rule harmless and always occurs in 

 the human intestine, closely resembles the typhoid bacillus. The comma bacillus 

 of Asiatic cholera, Vibrio cholerae (Fig. 257 k), was discovered by K. KOCH. It 

 occurs in the intestine as short curved rods with a single polar flagellum, and 

 sometimes in longer chains of spirally wound cells. Spirocliacte obcrmeicri, which 

 consists nf long, thin, spirally wound filaments, without Hagella, but capable of 

 motion, occurs in the blood during the attacks of relapsing fever, of which it is 

 the cause. 



Besides the above injurious parasites there are others which are more or less 

 harmless occurring on the mucous membranes, in the mouth (Fig. 4), or the 

 intestine. Sarciim ri'iitricvli, which occurs as packets of cocci in the stomach and 

 intestine of man. will serve as an example of these. 



