324 The Closing of the Wounds in the Larval Necturus 
of the wound as shown in Fig. 8. At this time there are no features 
which enable us to say just where the line of coalescence exists. Mitoses 
are found frequently, but from several counts on both the normal and 
wounded at this stage one finds neither an increase or a decrease. A 
condition strikingly similar to this has been described and figured by 
Barfurth in Rana. 
The condition 24 hours after excision is shown in Fig. 9. At this 
time one can still distinguish the original thickened margins of the 
epidermis, although they are becoming less and less pronounced. The 
cuticle has reappeared and is of the normal thickness and appearance. 
The gland cells in the epidermis are decidedly decreased in number ; only 
a few being seen in the entire series of sections passing through the area 
of the wound. The mitotic figures are somewhat more numerous than in 
the normal condition. The dermal chromatophores show a migration 
toward the median line and the underlying connective tissue is present. 
The section represented in Fig. 10 is from a larva 120 hours after 
excision. There is but the slightest indication of the line of fusion of 
the thickened margins of the wound. The epidermis being throughout 
nearly normal in appearance. The cuticle is as in the normal. One of 
the most striking features which has already been mentioned in the sur- 
face study is the almost entire absence of gland cells. Concerning their 
degeneration and regeneration but little is known and the material at 
hand does not permit a detailed description of these processes. All the 
structures have the appearance of the normal excepting the laver of 
chromatophores which has not extended completely over the original 
wounded surfuce. 
RESUME. 
It may be remarked that wounds of the skin of the larval Necturus 
close so rapidly, that a wound 1 mm. in width closes in less than two 
hours. By raising the temperature some four degrees C., the rate of 
closing may be increased about one-third. Fraisse states that in Siredon, 
a wound 2 mm. wide completely closes in five to six hours. In the same 
animal Barfurth found that when the tail was amputated the epithelium 
covered the wounded surface in about 75 minutes. 
In the closing of the wound there is a movement of both the epidermis 
and dermis toward the center of the original wound. In this process the 
epidermis moves much more rapidly than the dermis as has been observed 
by Fraisse, Peters, Barfurth, Loeb, Strong and others in various 
amphibia. 
