338 



BOTANY 



PART II 



to a rot of Hyacinths ; Bacillus 2)liytophthorus, which attacks the potato ; and 

 Bacillus Oleac, which gives rise to the Canker of the Olive Tree ("*). 



The numerous pathogenic Bacteria are the most important causes of infectious 



a. 









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c. 



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Fig. 247. — Pathogenic Bacteria, n, Pus cocci ; h, erysipelas cocci ; f, gonorrhoea cocci ; d, splenic 

 fever bacilli ; e, tetanus bacilli ; /, diphtheria bacilli ; g, tubei'cle bacilli ; h, typhoid bacilli ; 

 i, colon bacilli ; k, cholera bacilli. (From A. Fischer, VorJcs. iibei- Bacterien, x about 1500.) 



diseases. Their injurious influence on the tissues and blood of men and animals 

 is brought about by the excretion of poisonous substances, to which the name 

 toxins has been giveu. The following forms may be mentioned. Stuijhylococcus 



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ky 





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a h c 



Fio. 248.— Stained preparations from Ziegler'.s Text-hook of Pathology, a, Gonoeocci in the 

 gonorrhoeal discharge, mucus and pus corpuscles with cocci (methylene blue and eosin), x 700 ; 

 b, tubercle bacilli in sputum of ]ihthisis (fuchsiii and methylene blue), x 400; c, splenic fever 

 bacilli in the pustule of the disease (methylene blue and vesuvin), x 3o0. (From A. Fischer, 

 Vorles. iiber Bacterien.) 



2)yocjenes (Fig. 247, a), the cocci of which form irregular or racemose masses, is 

 the most common cause of suppuration, while Streptococcus pyogenes (Fig. 247, I), 

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

 Micrococcus {Diplococcus) gonorrhoeae (Figs. 247, c, 248, a) has somewhat flattened 

 cocci arranged in pairs, and causes gonorrlioea. Bacillus anlJiracis (Figs. 247, d, 

 248, c) was found by K. Koch in the blood and organs of animals suffering from 



