246 C. J. MARTIN. 
three experiments in which under these conditions a tracing of 
the arterial blood pressure was taken, this ‘was maintained at, or 
a very little below the original height, for some ten minutes after 
the power of the animal to breathe, had absolutely disappeared. 
In these experiments shortly before the cessation of ordinary e 
respiration the abdominal skin reflex which is so strongly marked 
in rabbits could no longer be elicited, and its disappearance was 
followed by that of the corneal reflex also, while at the same time 
the efficiency of the circulation was maintained, as was shown by 
the blood pressure remaining as high, or nearly as high as at the 
commencement of the experiment. 
(a)—Effect of venom on the reflex activity of the spinal cord in Frogs. 
After the introduction of ‘01 gramme of venom into the dorsal 
lymph sacs of frogs, the animals soon show signs of advancing 
paralysis. In about ten to fifteen minutes after the inoculation, 
the respiratory movements become slow, and eventually ceas 
It now responds only sluggishly to cutaneous stimulation, and if 
turned over on its back can with difficulty regain the prone 
position, on account of the incoordination of its efforts. A few 
minutes later the animal is quite unable to turn over, when placed 
on its back, and responds slightly or not at all to every form 
cutaneous stimulation. In about twenty minutes it is absolutely : 
paralysed, and even stimulation of the central end of a divided a 
Sciatic nerve is unable to produce the slightest reflex response. :. 
Now it is obvious that one cannot draw any conclusions concert 
ing the direct action of the poison upon the nervous system from 
such an experiment, as suspension of the circulation produces the : 
ae 
ag 
a 
If a frog in this condition be opened, the heart may be beating : 
feebly, but in most cases the whole circulation is thrombosed. 
same result. Thrombosis may however be obviated, as I have : 
previously mentioned by raising the temperature of the venom — 
solution to 85° C. before injecting it. In the remainder of my 
experiments on frogs this was done; ‘Ol gramme of this 
venom never produced thrombosis, but the animals show 
od the 
