68 
ZOOLOGICAL EXERCISES. 
Trace this backward, cutting the floor of the pulmo- 
nary sac, and, if necessary, turning to the right the 
orange albumen gland of the reproductive system, 
and the coils of the intestine. Observe the dilatations 
of the crop, and the pyriform cecal pouch going off 
to the right. Gradually clear away the stomach and 
the globular hard gizzard. Observe the entrance of the 
hepatic duct from the liver, which organ occupies a 
large portion of the spiral portion of the animal. 
Trace the intestine from the pyloric end of the 
stomach, passing forward on the left side straight to 
the heart, thence backward, and after making about 
five left-handed coils round the albumen gland, 
passing straight forward on the right side to the anus. 
Cut through the cesophagus above the crop and the 
rectum ; detach the whole alimentary system and place 
on a slide with salt water. Cut off a small portion 
of the intestine and examine with the quarter objec- 
tive—observe the cilia. Do the same with portions 
of the stomach and cesophagus. Cut open the 
gizzard; make a thin section, tease ib out with 
needles, and examine the muscular tissue with the 
quarter objective. Examine a portion of the liver. 
Notice the dark brown concretions. Follow up the 
part of the cesophagus that has been left, towards the 
head. While dissecting this out, the coiled muscular 
penis will be found to the right. Neglect this for the 
present, and carefully follow the cesophagus towards 
the mouth. Notice the yellow cerebral ganglia. Cut 
the cesophagus behind the nervous system and draw 
the cut part forward through the nerve collar. Detach 
the pharynx by cutting round the mouth, and lay it 
on a glass slide for examination. Observe the sali- 
