10 
president’s address. 
bacteria are morphologically intermediate between the micrococci 
and the bacilli. The spirilla have, as their name implies, a spiral 
form. The micrococci are said to abound in the atmosphere, 
comparatively few being found in sewer air, whilst the reverse 
holds good as regards the bacilli. The medical bacteriologist does 
not, however, rely exclusively upon the morphological characters of 
the micro-organisms he suspects are the causes of disease, in which 
case he would be often led into error, as it is self-evident the mere 
outside form and contour of these lowly organisms must present 
infinitely less variety than is met with in the higher forms of 
vegetable life. It seems astonishing, and well-nigh incredible, that 
these lowly organisms react so differently wnen subjected to various 
physical and vital tests. Some are readily stained by this colouring 
agent, others by that. Some grow freely in this nutrient fluid or 
solid, others in that. Some liquefy gelatine, others do not. The 
growth or multiplication of some is slow, that of others rapid. Last, 
not least, there is the inoculation test. One of the inferior animals 
is inoculated with a pure cultivation of the microbe under 
investigation, and, if a specific disease manifest itself, the causal 
relation between the microbe and the malady in question does not 
admit of any doubt. 
As it would be impracticable to describe all the micrococci and 
bacilli met with in disease in the short time allotted me for this 
address, I must limit your attention to those disease-germs which 
are the cause of constitutional diseases, leaving out of sight those 
which act only locally on the body, as well as those which, though 
believed by some, are not yet universally acknowledged as the 
prime factor in the disease they are supposed to generate. 
The micrococcus of Erysipelas is a streptococcus, that is to say, 
the individual cocci are clustered together after the fashion of 
grapes on a bunch. There can be little doubt of its causal 
relationship to erysipelas, and the fact the disease so often springs up 
spontaneously, as it were, shows that the micrococcus of erysipelas 
is not an obligative parasite, but is capable of existing outside the 
bodies of men and animals, on dead organic matters. About 2,400 
persons die annually of this disease in the Unitod Kingdom. 
