416 APPENDIX. 



ments are more definitely grouped into regions — viz., head, 

 tljorax, 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. 



Vertbbkata. — 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 



