VASO-MOTOR NERVES AND NERVE-CENTRES. 281 



merits than they commonly do while travelling in the blood- 

 current. The platelets, also, which are normally confined to 

 the axial currents, now pass towards the sides. If this stage 

 of very early inflammation pass on to the next, it is observed 

 that white corpuscles and platelets both stick to the inside of 

 the vessels. The platelets next adhere together and break 

 down into granular masses, and the white corpuscles thrust 

 amoeboid processes between the lining-cells of the capillaries 

 and smallest veins, and begin to push their way through. By 

 these means a considerable impediment to the blood-flow is 

 caused, and the circulation becomes slower, though all the 

 vessels of the part may be dilated. If the inflammation con- 

 tinue, many white corpuscles pass quite out of the vessels 

 (migration) and enter the neighboring lymph-spaces: the 

 red corpuscles get blocked and squeezed together into a mass 

 in which their individual boundaries are indistinguishable, 

 and some of them may even be squeezed through the walls 

 of the capillaries (diapedesis). Next all blood-flow in the 

 area under observation may be stopped, while more lymph 

 than normal collects in it. From this state recovery may 

 take place; or continued inflammation may lead to destruc- 

 tion of the part. The primary local disturbances in the cir- 

 culation seem due to changes in the inner coats of the vessels 

 of the irritated region; but an extensive continued inflam- 

 mation produces fever and many other secondary general 

 results, partly through the absorption of disease products 

 from the inflamed part and partly through irritation of 

 afferent nerve-fibres which throw various nerve-centres into 

 abnormal action. 



