24 



eggs in" a cocoon-shaped mass, covererl with a tough, glutinous secretion, 

 varying in number from fifty to one hundred. This may be a very common 

 method, but is by no means universal. It is the method followed by the 

 migratory locusts of Europe, and, from what I learn, I am' satisfied it is the 

 same with the destructive migratory species {Caloptenus spretus) of -the 

 West; but it is not the method followed by Aa-idium americanum, whicli I 

 have noticed digging into and depositing its eggs in the hard-trodden ground. 

 I have also obtained the eggs of C. femur-ruhrwn in rotten wood, where they 

 were placed, without any apparent regularity, and without connection by any 

 glutinous secretion. Mr. S. I. Smith has noticed the same thing in regard to 

 Chlcmltis conspersa, except that the eggs are placed in two rows. 



All the species, so far as I am aware, lay elongate-cylindrical eggs, those 

 of Clilceultts cotispersa, according to Mr. Smith, being about 0.25 of an inch in 

 length, while those of CEilipoda coralUpes, according to iny own observations, 

 are about 0.80 of an inch long, and slightly bent. The young of the latter 

 species, just before leaving the eggs, are exactly like the young larva, the legs 

 being neatly folded against the sides of the venter and sternum, the tarsi 

 resting against the sternum ; the antennae are laid down over the sides of the 

 face. 



The eggs are usually laid in the latter pai't of the summer or in autumn, 

 and remain in their place of deposit until the following spring or summer, 

 when they are hatched ; yet it would appear, from the number of larvas we 

 often see late in autumn, that some species in the southern and central portions 

 of the United States produce more than one brood in the year; but our 

 information is not sufficient to speak positively on this point. 



These insects attain their full growth by simple moltings, the larvae 

 and pupae resembling the perfect form, except in size and development of the 

 wings. According to Zinnani, the Italian Calopteni undergo their first molt- 

 ing about the fortieth day after exclusion from the egg, the second about 

 twenty days afterward, and the third about sixteen days later; but the num- 

 ber of moltings does not appear to be uniform in the different genera, six 

 being the number usually given by the different authors. According to 

 Koppen,* Pachytylus migratorius moults four times, the fourth moult pro- 

 ducing the perfect insect. 



The sounds which aremadebytheAcrididae, according to Mr. Scudderatid 

 * HoriB Soc. Ent. Eoss., iii., pp. 89-246, teste Zool. liec, IV, (1807). 459. ' 



