154 m'intosh, on young salmon. 



surface. No vein as yet carried back blood. Then a vein, 

 running parallel with the bent corda (origin of the cardinal) 

 "was observed to commence its current, and soon carried it on 

 most vigorously. This was due to the fact that the main 

 arterial trunk tunnelled a channel in the clot, and poured its 

 contents into the vein. Very rapidly, however, the vein 

 ceased to carry back so much, and finally stopped altogether ; 

 and the arteries, which for some time had been diminishing, 

 grew indistinct, sending only a few corpuscles in single file. 

 The clot soon became blanched (from solution and dispersion 

 of its hsematoglobulin), and the cut border had its margin 

 roughened in a few hours. In eight or nine hours the tip of 

 the corda is protected by a continuation of the cellular 

 border, and there is a considerable increase on the margin of 

 the wound below this. Where the incision is close to the bend 

 of the corda (between a b and b c) bleeding takes place to a 

 greater extent, but the artery slightly contracts, and a clot 

 forms. The animal respires slowly, gasps, and the heart is 

 pale and slow in action. In this condition it is then seen 

 that the aorta also grooves a channel in the clot and pours its 

 contents at once into the vein. When the incision was on 

 the proximal side of the bend of the corda (through b c) this 

 peculiar channelling of the clot did not occur, but the current 

 of the artery passed into the vein after a time by a communi- 

 cating branch — before reaching the border of the wound. 

 The animal will live for three or four days after the body is 

 severed through the fatty fin, showing the comparatively unim- 

 portant part played by the posterior part of its body at this 

 stage, whereas a wound of the yolk-sac is generally fatal. 



Kegeneration takes place very rapidly in wounds inflicted 

 on the young fish from six to ten days old. For instance, 

 when pieces (d) are removed from the fatty fin, the edges in 

 twelve hours are found papillose from cellular processes, and 

 the angles rounded, while the wound, which formerly was 

 spade-shaped, has now the form of a V, the new texture being 

 readily detected by its paler hue. The same ensues in inju- 

 ries of the tail. When the wound has been deep and some- 

 what narrow an arch of new texture closes in the cavity 

 before cicatrization takes place at the sides. Considerable 

 portions cut from the pectoral fins are also reproduced. 



