IIQ 



THE BIOLOGY OF THE ANIMAL 



they movable ? Of how many joints does each 

 consist ? Are the palpi appendages ? Draw 

 the labium with its palps attached. 



(d) The maxillse or " soft jaws." — Number? 

 Position? Does a maxilla in any respect re- 

 semble the corresponding part of the lobster? 

 See if you can find the protopodite consisting 

 of cardo and stipes, the endopodite consist- 

 ing of the lacinia and the galea. What is 

 the exopodite ? 



(e) The maxillary palpi. — Compare these in 

 every respect with the labial palpi, and draw a 

 maxilla with its palp. 



(/) The mandibles or "hard jaws." — Com- 

 pare in every respect with the maxillae. In 

 which direction do the mandibles open? To 

 what are they connected ? Draw. 



Push the outer mouth parts aside and find 

 (g) The tongue. — Study its position, shape, size, 

 structure, etc. Does it bear appendages ? 

 Does the head show indications of being composed of 

 segments ? If so, of how many ? In the locust is ceph- 

 alization carried to a greater or less extent than in the 

 lobster? "Why? Judging from the number of pairs of 

 appendages or traces of such, of how many segments 

 does the head consist? 



Make enlarged drawings of the head as seen from the 

 front and from the side, showing in each case all of the 

 structure visible. 



c. The thorax. — What proportion of the body does it 

 form? Of how many distinct pieces is it com- 

 posed ? What appendages does it bear ? How 

 are they situated ? 



