ENEMIES OF PLANTS. 295 



be well to pieserve some of them in a solution of forma- 

 lin (made hv mixing one part of formaldehyde, 40 per 

 cent., with 19 parts of water) for museum s[)ecimens. If 

 possible, have each stage of every species represented in 

 your collection of specimens. 



2. The Grasshopper. — Find tlie three l)(idy divisions — 

 head, thorax, and abdomen. 



The Head. — (1) Find tlie antennce (slender feelers). 

 How many segments in eacli ? Draw. 



(2) Find the compound eyes. Examine a portion of one 

 under the low power of the microscope. What is the 

 general shape of these parts, or facets, of the eye ? Draw 

 several of them. In wlaat direction can the grasshopper 

 see ? 



(3) How man}'' ocelli, or simple eyes, do you find ? 



(4) Mouth-parts. — [a) Find the lahruin, or upper lip. 

 Lift and remove it. Draw. 



{b^ Note the mandibles, or true jaws, exposed by the 

 removal of the labrum. In wliat direction can j'ou move 

 them ? Take out one. Draw. Does the grasshopper 

 obtain its food by biting or sucking ? 



(c) Find the labium, or lower lip. Remove it. Draw. 

 Is it a single appendage or two united ? 



{il) Look for the labial palpi attached to the labium. 

 How many segments in each palpus 1 



(f') Find the w^j;;/'//^, just in front of the A?/^///;//. These 

 each consist of three parts united at the base ; the outer 

 one, the maxillary palpus; the middle one, a spoon- 

 shaped piece, the galea; the inner piece, the laciniuy 

 [maxilla proper). Draw. 



(5) Take a fresh specimen and draw a front view of 

 the head, labeling all the parts.* 



* Every question in the above outline should be answered by- 

 actual observations upon the insects. It may be that the student 

 will be better able to answer some of these questions, after hav- 

 ing made the laboratory study of tt.e live insect. 



