MODE OF ENTRANCE. 



may divide and subdivide, and give rise to collections 

 of little bioplasts "granular corpuscles," as seen in 

 cases of inflammation of the pia mater, and also in 

 cases of tubercular disease of the same membrane. 

 The walls of the vessel are weak and liable to altera- 

 tions in the situation of these nuclei, as the latter 

 increase or diminish in size. Hence there is no diffi- 

 culty in accounting for the passage of minute par- 

 ticles of the living contagious bioplasm in cases in 

 which the capillary walls are diseased, and after they 

 have been unduly stretched and have remained some- 

 what flaccid. 



Now, the state of things referred to above a soft 

 moist state of the mucous surfaces, a dilated con- 

 dition of the capillaries, combined with a weak, 

 flaccid state of their walls, which always follows 

 long-continued congestion, and which is intimately 

 connected with a weak heart's action and feeble 

 condition of the nervous system, are the very conditions 

 which would facilitate the passage of living germs, 

 and is not this the state of things which exists in the 

 organism about to be the victim of a contagious fever ? 



No doubt in these cases the composition of the 

 blood is altered and its fluid constituents manifest a 

 tendency to permeate the vascular walls more readily 

 than in a perfectly healthy state. Such a state of 

 blood would doubtless affect the action of the nervous 

 centres presiding over the contraction of the arterial 

 walls, and regulating the flow of blood through them, 



