W. W. SWINGLE 511 



showed upon microscopic examination a turgor of the lymph spaces, 

 and finally after several hours more (the longest 48) all larvae were 

 edematous. The mortality was very shght up to 36 hours. After 

 this time, the extremely edematous larvae usually burst, unless killed 

 and preserved in fixing fluids. Rupture of the body wall usually 

 occurred at the point of operation. 



Several greatly swollen larvae were observed to burst while being 

 examined. These were at once placed in separate containers and 

 carefully watched. Several hours later these same larv« were again 

 observed to be edematous. They were then left over night. Two 

 were found dead the next morning. The remaining two had burst 

 again during the night; they recovered but again became edematous 

 and were finally killed. 



Partial Nephrectomy. 



In 50 larvae the glandular portion only of the right or left pro- 

 nephros was extirpated. The larvae averaged 6.5 mm. in length. 

 At the end of 24 hours, only three larvae showed indications of edema 

 and, in all three, the edema was confined chiefly to the side from 

 which the pronephros had been removed. All the larvae showed 

 swelling and hypertrophy of the remaining uninjured pronephros. 



38 hours after the operation half the larvae of the culture was ede- 

 matous. In the early stages, the swelling was almost always on the 

 side from which the kidney had been removed. Dissection of the 

 pronephros remaining showed the tubular complex to be much hy- 

 pertrophied and distended with fluid. A comparison of the pro- 

 nephros of such larvae with those from normal controls of the same 

 age showed a difference in size, though we should expect it in such 

 cases. 



The onset of edema in the larvae of this group was very much slower 

 and less marked than in any other culture of the larvae. In fact, 

 fully one-half showed only slight edema, which was confined chiefly 

 to a slight turgor of the submaxillary lymph sinus. 50 hours after 

 the operation ten larvae were counted which showed no edema what- 

 ever, and no indication of rupture of the body wall. It is clear that 

 the mesonephros of these larv« was beginning to function. 



