THE MICROSCOPE IN ETIOLOGY. 341 



of research than the other, and are therefore given here 

 in abridged form. 



Dr. Beale objects to calling disease-germs parasites, 

 since parasites are organisms themselves, and not mere 

 particles of living matter. He freely admits the great 

 variety and rapid growth of microscopic fungi and algae, 

 and the readiness with which they may enter and traverse 

 the textures of the body, but considers them to be but 

 seldom the cause of disease. He says, " In every part of 

 the body of man and the higher animals, and probably 

 from the earliest age, and in all states of health, vegetable 

 germs do exist. These germs are in a dormant or quies- 

 cent state, but 'may become active and undergo develop- 

 ment during life should the conditions favorable to their 

 increase be manifested. There is not a tissue in which 

 these gerrns do not exist, nor is the blood of man free 

 from them. They are found not only in the interstices of 

 tissues but they invade the elementary parts themselves. 

 Multitudes infest the old epithelial cells of many of the 

 internal surfaces, and grow and flourish in the very sub- 

 stance of the formed material of the cell itself. In many 

 very different forms of disease these germs of bacteria, 

 and probably of many fungi, are to be discovered in the 

 fluids of the body, but the evidence yet adduced does not 

 establish any connection between the germs and the mor- 

 bid process. The diseases known to depend upon the 

 growth and development of vegetable organisms are local 

 affections, and the structure of the organism can be made 

 out without difficulty, but contagions are general affec- 

 tions, and no such success attends our efforts to prove 

 that vegetable organisms are the active agents. In fact, 

 the fungi which commonly grow on the surface and in 

 other parts of the body do not produce disease. The germs 

 of fungi may remain perfectly passive in healthy textures, 

 growing and multiplying only in those which have already 

 deteriorated in consequence of disease or old age." . 



