512 ON THE INTERDEPENDENCE OF SCIENCE 



treatment will probably ever be able to cope with them. But taking all cases 

 together, it seems probable that Behring's hope that the mortality may be 

 reduced to 5 per cent, will be fully realized when the public become alive to 

 the paramount importance of having the treatment commenced 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 bacteriological, 

 has intimate relations with bacteria. If a 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 proto- 

 plasm, 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 b}^ 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, amoebae. It was 

 a somewhat weird spectacle, that of seeing what had just before been coursing 

 through our veins moving about like independent 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 continue 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 con- 

 nected 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 move- 



