MOVEMENTS OP LOCUSTS. 27 



Chapter 8 will be found to contain all that is at present accurately 

 known on the general habits and natural history of the species, bring- 

 ing out a number of, new facts and correcting some errors which have 

 heretofore prevailed. We would call especial attention to the por- 

 tions which treat of the locations where eggs are preferably laid, the 

 conditions of soil which most assist hatching, the general habits of the 

 young, and to the two subchapters, which show that in the temporary 

 region, south of the 44th parallel, the return migration to the North- 

 west is so complete that no insects of any consequence remain in the 

 autumn, and in which are given the reasons why, in said region, the 

 eggs are never laid thickly for two consecutive years, and, as a conse- 

 quence, severe injury in spring and early summer for two such consecu- 

 tive years never takes place. We have also discussed here the philoso- 

 phy of the migrating habit, showing pretty conclusively that it is not 

 to be attributed to one cause alone, but to several causes. 



The chapter on embryology and anatomy contains observations on 

 the mode of growth and hatching of the embryo, and gives new facts 

 regarding the external structure of the locust and the internal anatomy 

 of the respiratory organs concerned in lightening the body during flight. 

 The general and minute anatomy of the digestive system and of the 

 nervous system is also for the first time given. 



The chapter on transformations will be found interesting as giving 

 exact knowledge on the number of molts suffered by the species, mode 

 and manner of molting, and of getting wings, and the structural changes 

 that take place during growth. 



In chapter 11 will be found an illustrated account of all the more 

 minute enemies of the locust that are known to attack it in this country. 

 Several interesting scientific discoveries are recorded, and among these 

 we would draw especial attention to the interesting transformations of 

 the locust-mite, which is parasitic in its early 6 legged state upon the 

 mature insect, and in its adult 8-legged state destroys the locust-eggs ; 

 also to the curious life-history of the blister-beetles, which in their larval 

 state turn out to be locust-egg destroyers. The excessive multiplication 

 of most of these natural enemies was very generally noticed during the 

 past year, the ground in some places being red with the egg-feeding 

 mites, and the air full of swarms of the Tachina-flies, from which come 

 the maggots that eat out the vitals of the locust. 



In chapter 12 are given the locust-feeding habits of many western 

 animals not heretofore known to have that habit -, and the good offices 

 of birds are specially made manifest, examinations of the stomachs of 

 over 90 species and 630 specimens having been made with special refer- 

 ence to their locust-eating habits. The record in reference to these ex- 

 aminations is very full, giving the date, the locality, the common and 

 scientific names of the species, and the number of locusts and of other 

 insectsfound in each. The value heretofore placed on these aids by ento- 

 mologists is fully sustained by this record. 



