BACTERIAL PRODUCTS 17 



animals, in addition to man, from which he has been able 

 to isolate these parasitic amoebae, cultivating them from 

 the contents of the intestine in from twenty-five to one 

 hundred per cent, of the animals he examined. From this 

 he gathers that these parasites must have a wide, if not 

 universal distribution amongst vertebrates. He states : 

 * Amoebae were found in the intestinal tract of every species 

 from which cultures were made, from amphibians to man.' 

 In certain cases, these parasitic amoebae may undoubtedly 

 invade the tissues of their hosts. This has been proved 

 both in the human subject and in the pig. In the former 

 in cases of tropical abscess, in the latter in hog cholera 

 (Theobald Smith). 



Both organic and organised ferments, in breaking up 

 complex and vegetable animal bodies, frequently produce 

 substances of great activity. The emulsin the ferment 

 of bitter almonds gives rise to a hydrocyanated oil. The 

 my rosin of mustard seed develops the acrid mustard oil. 

 The protoplasm of particular plants produces their respective 

 alkaloids, some of which are active poisons. Certain mush- 

 rooms produce the poisonous alkaloid muscarine ; putrefy- 

 ing yeast yields sepsin ; from putrefied maize is obtained 

 an extract which contains one substance which tetanises, 

 and another which narcotises. Animal bodies invaded by 

 bacteria undergo decomposition, and the bacterial cells, 

 according to their kind, elaborate their respective alkaloids, 

 some of which are poisonous. Under healthy conditions 

 they are excreted, but if retained they are injurious. In the 

 healthy muscles of living animals, after active exertion, 

 there are found alkaloids allied to xanthin and creatin. 

 During digestion of fibrin by pepsin an alkaloid is formed. 

 Bouchard has stated that the alkaloids formed in the 

 intestines of a healthy man in twenty-four hours would 

 suffice to kill him if they were all absorbed and excretion 

 stopped. 



The pathogenic, like the putrefactive bacteria, when they 

 invade the bodies of higher organisms, act as ferments, 

 cause disintegration of living tissues, and formation of alka- 

 loidal toxins, and, besides, produce globulins or albumoses, 

 often as deadly as the alkaloids. Special local effects are 



B 



