DISSECTION OF THE FASCOLAR™ SYSTEM. 51 
after rt ws filled, and pushing up the prston-rod until 
the ingection flows from the end. 
To wnject the veins wt will be more convenient to tn- 
ject the supervor cava and inferior cava separately. Ln- 
troduce acannula filled with the blue injection into each, 
and then force tn the injection as in the arterves until 
the veins are well filled. A sponge should be at hand 
during the whole process to sop up any liquid or tnzec- 
tion material which may escape into the thoracic cavity. 
By this process of tngection the heart ts not left in good 
condition for dissecting, but this 7s supposed to have 
been done before. 
The injection of the arteries and veins can be made 
also from the femoralartery and vein of one of the legs, 
znjecting tn each case toward the heart and first wash- 
ang out the blood with salt solution. Thts method, 
however, 2s not so likely, en tnexperrenced hands at least, 
to give good results. After inzecting the animal must 
be left some little time before using to allow the plaster 
Lo sét. 
A, THE DESCENDING AORTA. 
Find the aorta gust beyond the arch, and dissect 
toward the postertwor. Lurn the heart and lungs 
toward the right, dissecting along the left side of the 
thorax. If necessary cut off the ribs on this sede nearer 
to the vertebral column. 
1, The Intercostal Arteries come off from the aorta 
in pairs in the spaces between the ribs; they pass out- 
ward along the lower or posterior margins of the ribs. 
The first intercostal from the aorta supplies the 5th 
or sometimes the 4th rib, giving a branch to the rib 
above. The 1st, 2d and 3d ribs are supplied by the 
superior intercostal artery (see below). 
2. The Bronchial Arteries arise either from the 3d 
