112 INVERTEBRATE ZOOLOGY. 



bles, and first untl second maxillae. (Remove these in the reverse 

 order for convenience and stiidy separately.) Compare each maxilla 

 • w^ith the typical first maxilla of the grasshopper, consisting of basal 

 piece, inner and onter jjlate, and i)alpus. In what waj^ does the sec- 

 ond maxilla diff:'er from the type V The first maxilla ? 



2. The body (=thurax + abdomen). .Study the appendages of the first 

 body somite, often called the maxilliped. Notice the inner plate 

 with its teeth, and the free leg. What is the probable nse of this 

 free part ? Notice a small opening on the inner side near the point. 

 This is the oi)ening of a poison gland. Compare this maxilliped with 

 the second maxilla and with a free leg. To what does the palpiis 

 correspond? Study a typical leg. How many joints? Can you 

 name them after the homology of the insect leg? [Type XVIII.] 

 Look at the last four legs for coxal glands. Is the last pair of legs 

 any different ? Why ? Compare with the anal stylets of crickets 

 and cockroaches. The somite posterior to the one bearing the last 

 pair of legs is the genital somite, in which is the median genital 

 opening. The appendages are changed into accessory genital organs. 

 Are there difi'erences in the two sexes V The final or anal somite is 

 withoiit appendages and contains the anal orifice. 



Type XVIII.— Caloptenus, sp? 



[Dissosteira {Oedipoda) the large form, with black and 3'ellow wings, or any 

 other true grasshopper (Acrididae) may be used here.] 



[As this is intended to be used as a preliminary study, the rules for dissection and other 

 technique will be given in full. Anatomical details, as relation, size and appearance of 

 parts, will also be given.] 



87. Collecting, choice of material, preservation, etc. The majority of 

 grasshoppers are hatched in the early summer and grow continuously until 

 Sept. -Oct., when swarms of large adults may be found everywhere. Obtain 

 a few large forms, which may be caught in the fingers or with a small net, 

 and select from them those having the following characteristics : Body broum- 

 ish above, yellow beneatJi. ; shanks of Idnd legs bright red : a conical spine pro- 

 jecting from the throat, just beneath the chin. This last is the most important 

 characteristic and indicates the group of grasshoppers known as Caloptenus. 

 If this form cannot be obtained, some other large species may be used, but 

 one must expect to find some slight variation from the description given here. 



