DESCRIPTION OF PLATES. 201 
Governments, by which scientific research has 
been stimulated and fostered, has not controlled 
our national legislators, and America has con- 
tributed but little to the advance of scientific 
knowledge in this direction. These researches 
present very great difficulties, owing to the mi- 
nute size of the micro-organisms which are be- 
lieved to be the cause of the diseases in ques- 
tion, and because of the multitude of harmless 
parasites of the same class (bacteria) which con- 
stantly infest the alimentary canal of man and of 
the lower animals. These quickly invade the 
blood and the tissues after death, and possibly 
before death, and have frequently been described 
by untrained observers as veritable disease-germs. 
This has led to great confusion and to contradic- 
tory statements from different sources, which have 
done much to retard progress, and have given some 
foundation for the ridicule with which certain well- 
meaning but only partially informed physicians 
are disposed to treat the whole subject. In view 
of these facts, investigators in this field agree that 
it is desirable to make photo-micrographs of these 
minute organisms, in order that slight morpho- 
logical differences may be detected. These would 
also assist greatly in the classification of the para- 
sitic bacterial flora of plants and animals and that 
of organic infusions to which floating atmospheric 
germs have access. 
