1881.] Entomology. 1007 
with which they may be in contact, that ee can smell natural 
food, have a sense of taste for food, but that the sense of touch is 
most highly developed. Worms are omnivorous, eating meat as 
well as leaves. How great quantities of leaves they drag under 
the ground, and how they undermine stones, and triturate in their 
stomachs small particles of stone, and thus act as geological 
agents is shown in this remarkable book. 
ENTOMOLOGY.’ 
RETARDED DEVELOPMENT IN Insects.2—In this paper the 
author records several interesting cases of retarded development in 
insects, whether as summer coma or dormancy of a certain portion 
of a given brood of caterpillars, the belated issuing of certain ima- 
gines from the pupa or the deferred hatching of eggs. One of the 
most remarkable cases of this last to which he calls attention, is the 
hatching this year of the eggs of the Rocky Mountain locust, or 
western grasshopper ( Caloptenus spretus) that were laid, in Sih 
around the Agricultural College at Manhattan, Kans. T 
egos were buried some ten inches below the surface in the fall a 
1876, in grading the ground around the chemical laboratory. 
he superincumbent material was clay, old mortar and bits of 
Stone, and a plank sidewalk was laid above all. In removing and 
regrading the soil last spring, Mr. J. D. Graham noticed that the 
eggs looked sound and fresh,‘and they readily hatched upon expo- 
sure to normal influences, the species being determined by Pro- 
fessor Riley from specimens submitted by Mr. Graham. Re- 
markable as the facts are, there can be no question as to their 
accuracy, so that the eggs actually remained unhatched during 
nearly four years and a half, or four years longer than is their 
wont, and this suggests the significant question: How much lon- 
ger could the eggs of this species, under favoring conditions of 
dryness and reduced temperature, retain their vitality and power 
of hatching ? 
Putting all the facts together, Mr. Riley concludes that we are, 
as yet, unable to offer any very satisfactory explanation, based 
On experiment, of the causes which induce exceptional retarda- | 
tion in development among insects. It is a very general rule 
exceptions to the rule. The eggs of crustaceans, as ; Apus and 
Cypris, are known to have the power of resisting drouth for 
Six, ten or more years without losing vitality, while in some 
1 This department is pase by Pror. C. V. Ritey, Washington, D. C., to whom — 
_ €ommunications, books for notice, etc., should be sent. 
? Abstract of a paper nih before the Ene Section of the A. A. A. S. at 
Cincinnati. 
Rep. Ins. Mo, ; gs ist Rep. U. S. Ent. Com. . 
