326 "Wisconsin State Horticultural Socibtt. 



ment seen in sach grains, where blight was seen, but by 

 endosmosis. 



Mr. Grimn states that upon examining with the microscope 

 some particles of a lemon containing bacteria and spores of algas, 

 he saw a certain number of bacteria gather around a spore, and fix 

 themselves to it by one of their extremities. They did not pene- 

 trate it ; but when they left it, the spore had diminished in volume, 

 while the bacteria had taken a greenish color. 



The most important question in relation to their history is, do 

 they, by contagion, direct poison, or by their power to assimilate 

 the organic substances in which they are found, cause disease 

 and death, or are they but natural agents to hasten the resolution 

 of living organisms into their original elements, when decay has 

 already commenced ? Can they cause disease, or are they only 

 the result of it ? On this point there is a great diversity of opinion 

 among scientific men. A. great many experiments have been 

 tried to settle the question, but with such varied results as to cause 

 those best acquainted with the subject to be very non-committal 

 in expressing their opinions. Dr. Antoine Magnin, who has 

 given to the public the most complete treatise on the subject 

 yet published, in speaking of their effect in certain diseases, sums 

 up by saying, " We do not feel justified in adopting any definite 

 conclusions," and closes a volume of nearly two hundred pages 

 in regard to these germs with the statement, '* As to their 

 role in fermentations, in putrefactions, in contagious diseases, 

 and in surgical lesions, notwithstanding the considerable 

 number of labors of which bacteria have been the object in 

 these different points in view, it is not yet possible to define 

 it in a certain manner." Others, of whom the most prom- 

 inent are M. Louis Pasteur, the renowned French scientist, and 

 Dr. Koch of Berlin, hold that they are the primary and special 

 cause of disease; not claiming, perhaps, that there is not usually 

 some previous adaptation of the tissues affected which aids 

 their development, and that there may not be conditions of 

 vitality in the animal exposed to the attack which will give per- 

 fect immunity, but their power is such as to enable them to pro- 

 duce disease and death in a majority of cases. The wonderful 



