170 DISEASE GERMS IN VESSELS. 



these circumstances. In many kinds of inflammation 

 this commonly happens. 



Every one who has been in the habit of making 

 minute injections of the vessels of tissues must be 

 acquainted with the fact that little longitudinal 

 rents or fissures in the walls of the capillaries, quite 

 wide enough for a red blood-corpuscle to pass 

 through edgeways, are easily made. It is therefore 

 quite certain that particles can pass from the interior 

 of the capillary vessels outwards with the greatest 

 readiness, and without the occurrence of any actual 

 rupture of the vascular wall. There can, therefore, 

 be no difficulty in explaining how the passage of 

 disease-germs in the opposite direction in a similar 

 state of the capillary wall takes place. These little 

 particles, like other forms of bioplasm, possess 

 inherent powers of movement, and would easily 

 insinuate themselves through any slight fissure which 

 existed in the capillary wall. Such particles of 

 living matter are even capable of passing consider- 

 able distances through the interstices of various 

 tissues, like the living germs of some parasitic 

 organisms, which, as is well known, often traverse a 

 great extent of tissue before they arrive at the 

 spot where they undergo development. 



Again, it must be borne in mind that there are at 

 very short intervals in the capillary walls masses of 

 bioplasm (nuclei), which increase considerably in size 

 when supplied very freely with nutriment. These 



