ON THE REAL NATURE OF DISEASE GERMS. 851 
written/* The learned author of this sentence appears to 
have accepted the doctrine that each contagious disease is 
produced by a specific vegetable organism. Now it appears 
to me that the arguments upon which this view is based 
break down as soon as they are analysed and the facts 
advanced in their favour carefully investigated. This part 
of the subject has been already considered in my work ‘ On 
Disease Germs: their Supposed Nature/ It was also dis- 
cussed in my Report on the Cattle Plague, printed in 1866. 
I will now pass on to consider the actual nature of the 
living germs in various “ exudations,” some specimens of 
which were described and figured by me as long ago as 1863. 
Simple Exudation . — The transparent colourless fluid which 
moistens the surface of a superficial wound after it has ceased 
to bleed is poured out from the capillaries, or from the 
lymphatic vessels, or from both sets of vessels. This fluid, 
besides containing albumen in solution, contains multitudes 
of minute particles of bioplasm, which grow and multiply 
outside as well as within the vessels. These form fibrin and 
matters more or less allied to it, and perform an essential 
part in the healing process, or in the formation of pus, as 
the case may be. These minute particles of living matter 
are present in the blood and lymph in countless numbers. 
They are concerned in the production of fibrous tissue out- 
side the capillaries, a change which occurs in many patho- 
logical processes, and also in the production of pus-corpuscles, 
and other “ corpuscles ” in the same situation, in disease. 
All “ exudations” contain these particles of living matter. 
The following paragraphs are taken from a paper written by 
me in 1863 : * — 
<ff When the capillary vessels are distended, as in that ex- 
treme congestion which soon passes into inflammation, a 
fluid which possesses coagulable properties transudes through 
the stretched capillary walls. It is probable that in such 
cases minute and narrow fissures result, which, however, are 
too narrow to allow an ordinary white or red blood-corpuscle 
to escape, but, nevertheless, wide enough to permit many of 
the minute particles of the living or germinal matter (the 
existence of which in the blood has been already referred to) 
to pass through. The small protrusions upon the surface of 
the white blood-corpuscle might grow through the capillary 
walls, become detached, and pass into the tissue external to 
the vessels. Such minute particles of living matter external 
* “On the Germinal Matter of the Blood, with remarks upon the 
Formation of Fibrin.” Microscopical Society, December 9th, 1863. See 
‘ Trans. Mic. Soc.,’ April, 1864. 
