364 777^ BEGINNINGS OF LIFE. 



matter (either fluids or organisms) had the power of 

 setting up certain changes of a spreading character, 

 which soon sufficed to produce a condition of blood 

 similar to that usually preceding the development of 

 organisms in this disease. If the organisms acted quel 

 organisms, and not as ferments or producers of spread- 

 ing chemical changes in the fluids of the body, then we 

 should necessarily expect that other more or less similar 

 organisms would also be capable of multiplying them- 

 selves, and of producing general parasitic diseases. 

 This, however, is notoriously not the case. Fermenting 

 and semi-putrid articles of food, teeming with lower 

 organisms, are constantly eaten with impunity by the 

 lower animals, and are in many instances sought after 

 by man — nay, such articles of diet are occasionally 

 administered with the view of curing rather than with 

 the prospect of causing disease ^. We can only con- 

 clude, therefore, that in ^ the biood,' in ^ flacherie/ and 

 other similar affections, the contagious element acts as 

 a mere dead ferment might do in inciting blood- 

 changes j and that the organisms which are subse- 

 quently found in the infected animal are, for the most 

 part, the products of a new birth which has taken place 

 in the altered fluids ^. 



^ Take the case of ' Kousso,' for instance, which is lauded by some as 

 an excellent remedy for Phthisis. See also Appendix E, p. cxxiv. 



2 Other instances of a similar nature are known. Thus, it has been 

 ascertained by M. Vulpian ('Archives de Physiologic,' vol. i. 1868), 

 that the insertion of a small portion of cyclamen-root beneath the skin 

 of frogs produces local irritation and a putrefactive process, which, after 



