﻿114 EIGHTH ANNUAL REPORT 



regions of Missouri, Kansas, Iowa and Nebraska ravaged last Spring, 

 did so ; and if I may j udge from experience in our own State, those that 

 could not, perished, so that not a remnant of the army was left in theFall. 

 But whatever the causes, the fact of debility, disease and deterio- 

 ration in, as well as migration from, the more fertile southeastern 

 country the species occasionally devastates, stands forth clearly and 

 cannot be gainsaid. The following observations from careful observers 

 may be placed on record here : 



Mr. Riley is of the opinion that the grasshoppers run out in a tew generations 

 after they leave their native sandy and gravelly soil. My experiments so far as they 

 go, verify that opinion. For several years I have caught grasshoppers during early 

 summer that came fresh from the direction of the mountains, and by attaching their 

 legs with fiae silk threads to a small spring balance, found that their physical strength 

 was from twenty-five to fifty per cent, greater than that of grasshoppers treated the 

 same way that were hatched in Nebraska or in States further eastward or northward. 

 The same result was reached by caging them, and ascertaining how long they would 

 live without food, and also by vivisection. In some places, also, the eggs that were 

 laid in different years since 1864 did not hatch out. The changes from extreme wet to 

 dry, and from cold to hot weather, or some other unknown causes, seems to sap their 

 constitutional vigor. Were it not for this, long ere now these grasshoppers would, from 

 their enormous numbers, have desolated the whole country as far east as the Atlantic. 

 — [Prof. Samuel Aughey, of the University of Nebraska, in the Lincoln (Nebr,)Jo;«rwaL 



I have observed hundreds of winged locusts fall to the ground during flight, either 

 already dead or soon dying. These upon examination have generally proved to con- 

 tain no parasites, and 1 judge that their death was in consequence of impaired strength, 

 this second generation raised in an unnatural climate not equalling in vitality the first 

 generation and succumbing to the fatigue consequent upon extended flight. — [Prof. F. 

 H. Saow, of Kansas State University, in Observer of Nature. 



DEFINITION OF THE SPECIES. 



In defining the Rocky Mountain Locust last year, I endeavored to 

 show that we have three closely related forms or so-called species, viz. : 

 spretus, which, is the devastating species of the West; femur-rubrum^ 

 a somewhat smaller, shorter-winged species common over the whole 

 country, and Atlanis^ a still smaller species, but, except in size, ap- 

 proaching in general character nearer to spretus than femur-rubrum. 

 Careful study of the subject has convinced me of the correctness of 

 the definitions then given. In the report of the meeting of the Cam- 

 bridge Entomological Club, already referred to, we are told that: 



Mr. Scudder also doubted the specific and perhaps even the varietal rights of C. 

 Ailanis, described by Mr. Riley from the White Mountains, lor specimens of C. spretus 

 have been found in different eastern localities, and, like many other insects of wide lat- 

 itudinal distribution, have shorter wings than the western forms. Mr. Riley gives no 

 characters of importance to distinguish C. Atlanis from C. spretus. 



An opinion like this from one who has given much attention to 

 the Orthoptera might command respect were it not unjust and super- 

 ficial. All discussion at the present day as lo whether we are deal- 

 ing with species or varieties, is more or less puerile. Naturalists have 

 no fixed standard as to what constitutes a species, and are fast com- 

 ing to the conviction that there is no such thing in nature, and that 



