EEPARATIVE PROCESS. 565 



mined ; the healing may be perfected, or a slow uncertain process of repair may 

 be but just begun ; and the mutual influence which the injury and the patient's 

 constitution are to exercise on one another appears to be manifested more often 

 at or near the end of this period, than at any other time." The cessation of 

 this period of calm, and the active commencement of the reparative operations, 

 are marked by the restoration of the flow of blood in the vessels of the wounded 

 part; but the current is not altogether normal, being slower but fuller than 

 natural, so that on the whole more blood than usual passes through the capil- 

 lary plexus. This increased afflux of blood is followed by effusion of plastic 

 material in increased proportion; and it is from this effusion that the granulat- 

 ing process properly commences. The plastic material effused upon the surface 

 of an open wound is first developed into cells ; and these cells, in the deeper 

 portions of the effusions, are metamorphosed, into fibrous tissue, of which the 

 substance of the granulations is composed. Those which are formed upon the 

 surface, however, are converted into pus-cells ( 614); in some instances (as 

 Mr. Paget has pointed out) by degeneration from a higher development; in other 

 cases by an originally imperfect development : and thus the granulation surface 

 is constantly in a state of morbid action, and a large proportion of the plastic 

 material is completely wasted. The layer of pus, however, serves as a sort of 

 epithelium for the subjacent granulation tissue, in which we find not only a com- 

 plete formation of cells, but a commencement of the metamorphosis of these 

 cells into fibres, before bloodvessels make their appearance in the tissue. These 

 bloodvessels are formed by "out-growth" from the subjacent capillaries, in the 

 mode formerly described ( 295). From the investigations of Mr. Listen, it 

 appears that the vessels of the subjacent tissue are much enlarged, and assume 

 a varicose character. The bright red color of the granulations, however, does 

 not depend on their vascularity alone ; for the cells themselves, especially those 

 most recently evolved, are of nearly as deep a color as the blood-corpuscles ; and 

 the sanguineous exudation which follows even the slightest touch of the granu- 

 lating surface, does not proceed from blood effused from the newly-formed 

 vessels only; for the red fluid shed in this manner contains, besides blood-disks, 

 newly developed red cells, ruddy cytoblasts, pale granules, and reddish serum. 

 It is a common property of animal cytoblasts, that they present a reddish color 

 on their first formation, when in contact with oxygen ; but this hue they lose 

 again, whether they advance to perfect development and become integral parts 

 of a living tissue, or die and degenerate. 



606. The process of Suppurative Granulation, then, appears to differ from 

 the process of granulation as it takes place in closed wounds, or in a warm moist 

 atmosphere (the "modelling process" of Dr. Macartney), essentially in this 

 that a large part of the exudation-corpuscles deposited on the wounded surface 

 degenerate into pus in the former case, whilst none are thus wasted in the latter : 

 but that the existence of inflammation occasions a more copious supply of 

 fibrin in the former case, and increases its tendency to become organized; the 

 filling up of a wound with granulations being thus a much more rapid process 

 than that renewal of the completely formed tissues which may take place in 

 the absence of inflammation. The imperfect character of the granulation struc- 

 ture is shown, by the almost complete disappearance of it after the wound has 

 closed over. The portion of it in immediate contact with the subjacent tissue, 

 however, appears to undergo a higher organization ; for it becomes the medium 

 by which the cicatrix is made to adhere to the bottom of the wound. It is very 

 liable to undergo changes which end in its disintegration; as is evident from the 

 known tendency to re-opening, in wounds that have been closed in this manner. 



607. When two opposite surfaces of granulations, well developed, but not 

 yet covered with cuticle, are brought into apposition, they have a tendency to 

 unite, like the two original surfaces of an incised wound. This method of union, 



