134 



Scientific Proceedings (53). 



handled, and in ten minutes blood pressure had fallen to 98 mm., 

 and in 20 minutes to 56 mm. Hg. In 40 minutes there was still 

 31.6 vol. per cent. C0 2 in the arterial blood. 



In another experiment the intestines were exposed and aerated 

 (not handled). The C0 2 content of the blood was maintained by 

 connecting a long tube to the trachea. After one hour and a half, 

 blood pressure had changed but one mm. Hg and the animal was 

 in good condition. The intestines were then handled, and in ten 

 minutes the blood pressure fell from 122 to 60 mm. Hg. The C0 2 

 content was 45.1 per cent. In 25 minutes the blood pressure was 

 46 mm. Hg, the C0 2 content normal, and the dog in shock to such 

 a degree that the sciatic nerve could be dissected out without the 

 administration of ether, the animal making no movement what- 

 ever. In these experiments on the abdominal cavity the primary 

 factor concerned is unquestionably the manipulation of the intes- 

 tines, and not any diminution of C0 2 caused thereby. It will 

 be remembered that in the similar experiments of aeration of the 

 intestines, reported by Henderson, the intestines were " handled 

 gently." We have been unable to find that he notes any mention 

 of aerating the abdominal cavity beneath a celluloid membrane 

 with air as a control experiment. 



His control experiment, in which he did not secure shock, was 

 merely aerating the abdominal cavity beneath a celluloid window 

 placed in the abdominal wall with a stream of air plus C0 2 . 



The present experiment shows that aeration of the intestines 

 without the addition of C0 2 does not produce shock. 



87 (783) 



A note on the transmission of spiroch aetes. 



By John L. Todd. 



Leishman and other authors have shown that the anal and 

 coxal excretions voided by ticks {Ornithodoros moubata), capable of 

 transmitting spirochaetes (Spirochceta duttoni), are infective and 

 that susceptible animals inoculated with these fluids develop a 

 spirochaetal infection. It has been asserted that animals upon 

 which infected ticks have fed will not become infected, unless 



