1 882.] A Pathogenic Schizophyte of the Hog. 299 



can be sufficiently diluted to lose its efficiency. With living 

 germs it is different ; if conditions are favorable, a few of them 

 will suffice to develop innumerable generations, and may thus be- 

 come a source of incalculable mischief. Further, it is also well 

 known that the disease can be communicated through the air, 

 and that the infectious principle which may happen to be floating 

 in the air is absorbed by wounds, scratches, sores, abraisions, etc., 

 in skin and mucous membranes, which would hardly be possible 

 if a chemical virus constituted the cause and the means of in- 

 fection. 



5. The temperature of the atmosphere, and also the weather 

 have considerable influence as to the spreading of the disease, 

 but apparently have no influence whatever upon the morbid pro- 

 cess or the development of the disease, after an animal has be- 

 come infected. Frost, cold weather, lasting snow, frequent heavy 

 rains, and continued drought and sunshine retard, and mild, warm 

 and cloudy weather, heavy dews, and now and then a light rain 

 considerably promote the spreading of the disease. Such would 

 not be the case if the infection-, principle consisted in a chemical 

 virus, indestructible by water and air, but all this is natural, easily 

 explained and self-evident, if living germs which require a certain 

 degree of warmth and moisture, constitute the infectious princi- 

 ple, because frost, lasting snow, cold weather, heavy rains, and 

 continued drought are inimical to organic life and vegetation, 

 offer but little opportunity to the Schizophytes for a change of 

 place, and necessarily retard their development and propagation ; 

 while, on the other hand, mild and warm weather, heavy dews, light 

 rains, etc., are not only favorable to vegetation in general, and to 

 the development of minute organic bodies in particular, but also 

 offer a great many chances for a change of place and medium, 

 and thus promote the propagation of the Schizophytes. The latter 

 which are discharged in immense numbers with the excrements, 

 urine, discharges from the nose, and other secretions and excre- 

 tions of the diseased animals, rise into the air, perhaps mostly as 

 micrococcus-germs and micrococci, probably only to a limited 

 height, when the moisture contained in the dung and other excre- 

 tions, and the urine evaporate, and come down again in the dew, 

 and when it rains. At any rate, where swine-plague is prevailing, 

 the swine-plague micrococci can often be found in dew-drops on 

 the grass early in the morning, and also in exposed pools of 



