56 THE MIcROScoPE. 
this, cut through the pericardium and make an incision through 
each of the ventricles of the heart. Secure the pipe in the left 
ventricle and proceed. Toward the last, close the opening in 
the right ventricle. Use Seiler’s carmine gelatine. 
INJECTING FROM THE CAROTID ARTERY. 
A much neater way to perform the above operation is to inject 
from the carotid artery down toward the heart. I have repeat- 
edly tried this with good results. It can be so neatly performed 
that scarcely any blood is lost save that collected in the beaker, 
First cut down and expose the large artery and vein of the 
neck. Either dissect the vein out for a little distance and then 
cut it and hold the cut extremity over a beaker, or better intro- 
duce into the vein a small glass tube. Bleeding will freely 
occur through it. If a clot stops the flow, remove the tube and 
wash it out or introduce a wire and break it up. Then securing 
the filled nozzle in the carotid vessel. A small portion of the 
vessel is included between two clamps—flattened, bent wire— 
and a longitudianal slit made through its walls. After the pipe 
is well secured a small quantity of the carmine mass is slowly 
introduced. The beat of the heart itself will push the mixture 
on until this first small quantity is seen to color the gums and 
eyelids. Proceed as directed until the operation is complete; 
until considerable force is necessary to empty the syringe. 
Toward the latter part of the operation it may be desirable to 
open the abdominal cavity in order that the organs may pro- 
trude and become completely filled with the injection mass. 
When the gelatine has set, the tissues may be removed and 
hardened after the regular methods. 
—__—_so rm —__ 
AN ANIMAL OR PLANT? 
T. B. REDDING. 
ie find a drawing of an object that I observed last 
night under very favorable circumstances. I had often seen 
specimens of the same under the microscope, but they were 
always in a still condition, and would so remain for days. Last 
