ADDRESS. 25 
all cases together it seems probable that Behring’s hope that the mortality 
may be reduced to 5 per cent. will be fully realised when the public 
become alive to the paramount importance of having the treatment com- 
menced at the outset of the disease. 
There are many able workers in the field of Bacteriology whose names 
time does not permit me to mention, and to whose important labours I 
cannot refer ; and even those researches of which I have spoken have 
been, of course, most inadequately dealt with. I feel this especially with 
regard to Pasteur, whose work shines out more brightly the more his 
writings are perused. 
I have lastly to bring before you a subject which, though not bacterio- 
logical, has intimate relations with bacteria. Ifa drop of blood is drawn 
from the finger by a prick with a needle and examined microscopically 
between two plates of glass, there are seen in it minute solid elements of 
two kinds, the one pale orange bi-concave discs, which, seen in mass, give 
the red colour to the vital fluid, the other more or less granular spherical 
masses of the soft material called protoplasm, destitute of colour, and 
therefore called the colourless or white corpuscles. It has been long 
known that if the microscope was placed at such a distance from a fire as 
to have the temperature of the human body, the white corpuscles might 
be seen to put out and retract little processes or pseudopodia, and by their 
means crawl over the surface of the glass, just like the extremely low 
forms of animal life termed, from this faculty of changing their form, 
ameebe. It was a somewhat weird spectacle, that of seeing what had 
just before been coursing through our veins moving about like inde- 
pendent creatures. Yet there was nothing in this inconsistent with what 
we knew of the fixed components of the animal frame. For example, the 
surface of a frog’s tongue is covered with a layer of cells, each of which is 
provided with two or more lashing filaments or cilia, and those of all the 
cells acting in concert cause a constant flow of fluid in a definite direction 
over the organ. If we gently scrape the surface of the animal’s tongue, 
we can detach some of these ciliated cells; and on examining them with 
the microscope in a drop of water, we find that they will contiuue for an 
indefinite time their lashing movements, which are just as much living or 
vital in their character as the writhings of a worm. And, as I observed 
many years ago, these detached cells behave under the influence of a 
stimulus just like parts connected with the body, the movements of the 
cilia being excited to greater activity by gentle stimulation, and thrown 
into a state of temporary inactivity when the irritation was more severe. 
Thus each constituent element of our bodies may be regarded as in one 
sense an independent living being, though all work together in marvellous 
harmony for the good of the body politic. The independent movements 
of the white corpuscles outside the body were therefore not astonishing : but 
they long remained matters of mere curiosity. Much interest was called to 
them by the observation of the German pathologist Cohnheim that in some 
