46 
ZOOLOGICAL EXERCISES. 
the anterior portion the supra-intestinal vessel gives 
rise to a series of short sacs lying on each side of 
the cesophagus. These are the so-called hearts. 
6. Notice the grey muscular stomach, or gizzard, and the 
white male reproductive organs lying in front of it, 
Also observe the white tubular segmental organs, 
attached to the posterior side of each mesentric 
septum, on either side of the intestine. 
7. Lift up the supra-intestinal vessel with the forceps, and 
cut off a portion. Examine it with the microscope ; 
notice that with your highest power the red fluid 
contains no corpuscles. 
8. Notice the double cerebral ganglion lying on the 
pharynx, in the third segment. 
9. The alimentary system—Wash away with a brush 
the red fluid that will have exuded from the vessels ; 
cut the intestine across at the clitellum; lift up 
the anterior portion with the forceps, and at the 
same time cut with a knife the septa which 
hold it down. Observe the bright red swb-cntes- 
tinal vessel running along the interior surface 
of the intestine, and communicating with the 
supra-intestinal vessel by means of the transverse 
vessels. Cut very slowly and carefully while you 
are passing the reproductive system. Remove the 
whole of the alimentary canal, and lay it out, by 
means of a brush, in water on a glass slide, 
10. Observe the muscular pharynx, with many muscular 
fibres attached, narrowing into a long cesophagus, 
upon which, in the region of the reproductive organs, 
lie on each side the stalked globular esophageal 
glands. The cesophagus expands into a dark-coloured 
stomach, or crop, which is followed by the red 
