GRASSHOPPER. 79 



compound? What is the shape of the parts (facets) of 

 which it is composed? 



Look on the front of the head for the smaller bead-like 

 simple eyes or ocelli. How many of these do you find, and 

 how are they arranged? 



On the front of the head, below the eyes, is a broad fold, 

 the clypeus, to which is attached a movable upper lip 

 (labrum) covering the mouth in front. Near the eyes arise 

 two long, slender feelers, or antennce. Could they be re- 

 garded as jointed appendages? 



On the lower side of the head is the mouth, surrounded 

 by a series of appendages, or mouth-parts. Beginning be- 

 hind, remove these one after another with forceps and 

 needle. The most posterior is the lower lip, or labium. 

 It is in reality double, and consists of the united basal 

 joints and, arising from these on either side, a several- 

 jointed palpus. Draw the labium X 10, and then take off 

 and draw the pair of appendages, the maxillce, next in front. 

 Notice that in these the basal joints are enlarged, one 

 forming a sharp cutting-organ, the other a more fleshy 

 portion to hold the food in position. The terminal parts 

 form a palpus, somewhat similar to the labial palpus. 

 Still further in front come the jaws, or mandibles. Move 

 these with the forceps. Do they work in the same way 

 that your own jaws do? Draw them, and then draw front 

 and side views of the head, labelling all the parts. 



Have you found any traces of segments in the head? 

 How many pairs of jointed appendages have you found? 

 According to Savigny's law, how many segments * must 

 there be? 



* Study of the embryos of some insects makes it probable that 

 there is one more segment in the head than is shown by Savigny's 

 law. 



