Natural History and Transformations. 71 



last is laid, the mother devotes some time to filling up the 

 somewhat narrower neck of the burrow with a compact 

 and cellulose mass of the same material, which, though 

 light and easily penetrated, is more or less impervious to 

 water, and forms a very excellent protection (Fig. 9, d). 



PHILOSOPHY OF THE EGG-MASS. 



To the casual observer, the eggs of our locust appear 

 to be thrust indiscriminately into the hole made for their 

 reception. A more careful study of the egg-mass or egg- 

 pod will show, however, that the female took great pains 

 to arrange them, not only so as to economize as much space 

 as possible consistent with the form of each egg, but so as 

 to best facilitate the escape of the young locust ; for if, 

 from whatever cause, the upper eggs should fail to hatch, 

 or should hatch later than the lower ones, the former would 

 offer an impediment to the exit of the young in their endeav- 

 ors to escape from these last, were there no provision against 



such a possibil- 

 ity. The eggs 

 are,indeed,most 

 carefully placed 

 side by side in 

 four rows, each 

 row generally 

 containing sev- 

 en. They ob- 

 lique a little 

 crosswise of the 

 cylinder (Fig. 9, a). The posterior or narrow end, which 

 issues first from the oviduct, is thickened, and generally 

 shows two pale rings around the darker tip (Fig. 10, a). 

 This is . pushed close against the bottom of the burrow, 

 which, being cylindrical, does not permit the outer or two 



Egg Maps of Rocky Mountain Locust :— a. from the 

 side, -within burrow ; b, from beneath ; c. from above— en- 

 larged. 



