LiOcnst ( Caloptenus Sp.) 



Material. — Locusts, generally miscalled "grasshop- 

 pers," may be found in greater or less abundance in fields 

 and along roadsides, from midsummer until the early 

 frosts come. The largest specimens available should be 

 caught. Each student should have two or three speci- 

 mens of each sex. If this type is to be studied at a time 

 of year when living insects cannot be obtained, a suffi- 

 cient number of them should be preserved in alcohol. 

 They may be put when first caught into three to six 

 times their bulk of sixty per cent, alcohol for a day, and 

 then transferred to about the same quantity of eighty 

 per cent, to ninety per cent, for keeping. 



It is impracticable to try to keep these insects alive 

 during the winter. 



For the examination the student will need fine for- 

 ceps, small scalpel, fine scissors, hand -lens, dissecting- 

 needles, chloroform or ammonia, fifty per cent, alcohol, 

 metric scale, compound microscope, dilute hydrochloric 

 acid, and normal salt solution. 



Method of Examination. — Preserved specimens may 

 be studied without any further preparation. It is well, 

 however, to remove them from the strong alcohol in 

 which they are kept to a mixture of equal parts of fifty 

 per cent, alcohol and glycerine for about an hour before 

 beginning the examination. The stiffened muscles be- 



