HYDE: COLLATERAL CIRCULATION IN THE CAT. 169 



kept warm, and operated on with aseptic precautions. An in- 

 cision was made to the right of the median abdominal wall, the 

 intestines laid out on warm, moist, sterilized cotton, and the 

 postcava exposed. It was ligated anterior to the entrance of 

 the right renal vein, the wound sewed, and covered with collo- 

 dion. Within four days the kittens were dead. The }^osf. 

 mortem showed that peritonitis had set in, but a comparison of 

 the blood-vessels with those of the unoperated kitten showed 

 differences which encouraged the continuation of the investiga- 

 tion. 



Kittens a few weeks older were similarly operated on, and all 

 died within four days from peritonitis ( pui'ulent ?) . The re- 

 maining experiments were iDerformed on older kittens, with 

 greater aseptic precautions. I shall describe the condition of 

 one of those that had the postcava ligated below the liver, about 

 one centimeter anterior to the entrance of the right renal vein, 

 and which gave successful results. 



On|March 27 I operated on a young cat that had not been 

 fed for sixteen hours. During the two days that followed the 

 cat remained inactive, sleeping most of the time, and refused 

 food. The third day it walked slow^ly about and lapped milk. 

 The seventh day it was more active, but its walk was abnormal ; 

 the hind legs were not raised from the ground, but dragged 

 along ; this was, no doubt, due to the wound and to the altered 

 circulation. At the end of the second week it ran actively about 

 and seemed quite normal in every respect, and the wound had 

 entirely healed. 



Four weeks after the operation, the animal was chloroformed, 

 its venous system injected with colored starch, from the femoral 

 vein, and compared with that of a normal cat of equal pro- 

 portion likewise injected. In comparing the venous system of 

 the operated cats with that of the unoperated, the most striking 

 differences were the great increase of small vessels in the ligated 

 area, the large size of the lumbar, ileo-lumbar, adrenal, superior 

 intercostal, azygos and two longitudinal intraspinal or me- 

 ningo-rachidian veins. 



The cavity of the postcava was obliterated by the growing 

 together of the walls at the place of ligation. Some small an- 

 astomosing vessels had developed between the postcava anterior 

 and posterior to the ligature, between the postcava and the 



