AA 
18 Observations on the Pulsating Organs, etc. (January ” : 
From 4.20 P. M. to 9 P. M. seventeen distinct observations wend 
made, varying from one to seven minutes each. The actual time 
spent at the microscope during this period was forty-five minut 
For foùr minutes of this time the organ had been quiet. 
After 5.20 P. M. it gradually fell from 103 pulsations per minute — 
to 43 per minute, at 8.30 P. M.; from this time it began an increa 
that had reached 116 at 8.55 P. M. 
From 9 P. M. to 10.30 P. M. forty-seven minutes were spent 
the microscope, divided among thirty-six observations, the pulsa 
tions during this time gradually falling from 120 per minute to 
beats per minute.. . 
At 10.50 P. M. I retired, leaving the organ beating at 50 p | 
minute. . 
The following morning, Oct. 4, 1883, at 6.50 A. M., the org 
was not beating. Atg.50 A. M. regular observations were ag 
The rate varied from 67 to 24 beats per minute, being the greate 
part of the time at 55 per minute. 
No sudden transition of rate was observed in this specimen į 
the fall from 67 to 24 taking place gradually, the lowest limit 
having been reached, the rate would again increase to the high 
limit. Hot air blasts were several times blown over the micro 
scopic slide after the organ had been beating twenty-one hou 
The usual effect was to increase the rate and strength of beati 
for a short time. 
The other observations do not differ in any EEN particula 
from the one given above. They were all made in less ti 
however; the longer ones being several hours shorter than- 
-one detailed. 3 
The automaticity has also been noted in the amputated legs 9 
Notonecta and Corixa. . 
- The work on the histology of these organs has yielded, as | 
no definite results. 
‘To conclude, then, in my estimation the three points mentio! 
at the outset have been established, viz: 
(1) The pulsatile organs are separate from the muscular s; 
of the legs, 
(2) They influence circulation. 
(3) They are automatic. 
