416 
APPENDIX. 
merits are more definitely grouped into regions — viz., head, 
thorax, and abdomen—than in the other two animals (Fig. 98). 
Study the structure of each region, together with its append¬ 
ages, noting that the organs of locomotion are confined to the 
thorax, those of special sense mainly to the head (Fig. 262). 
Examine the outer wings, noting their structure, their position 
on the body when at rest, their point of attachment to the body, 
and compare with the second pair. Study also the legs—their 
position, structure, direction in which the joints bend ( Fig. 
131). Examine the foot closely, noting the pads and claws 
(Fig. 127). Look for spiracles along the side of the abdomen 
(Fig. 79), and in the females note the ovipositor at the end of 
the abdomen. Examine the head and its appendages, and com¬ 
pare with Figs. 22, 24. Study the mouth parts, and compare 
with Fig. 21. Examine the antennae (Fig. 147) and eyes (Figs. 
155, 156). With sharp scissors or scalpel cut open the body, 
and examine under water the arrangement of the internal organs, 
comparing with Figs. 41, 42. Harden specimens in alcohol; 
then accurately cut them in halves along the middle line of the 
body (Fig. 43). If recently killed specimens be opened under 
water, the larger air-sacs and tubes may be distinguished by 
their glistening appearance. 
Vertebrata.— A very good idea of the general structure of 
vertebrates may be obtained by the examination of a fish, a 
bird, and a mammal. As in the case of other animals, as much 
as possible should be learned from the living organism with re¬ 
gard to its habits, etc. If minnows are not obtainable, let 
the student have “goldfish,” which may be purchased at any 
bird-store, and which, with little trouble, may be kept in a small 
aquarium. Likewise, canaries and sparrows may be watched to 
learn some of the more obvious habits of birds. As for the 
mammal, a cat, dog, or rabbit may serve. 
Almost any scaly fish of moderate size, as a perch, may be 
used for dissection. The specimen may be laid upon a thick 
paper, a board, or a platter. Before opening the body, note the 
external characters: the shape of the body; its parts —viz., 
head, trunk, and tail, and their connection to each other; the 
color of the body and its covering, consisting of scales coated 
with a slime-like epidermis; the arrangement of the scales (Fig. 
102); the number and position of the fins (Fig. 123), their 
structure, and method of folding; the shape of the head; the 
