330 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



maker on the leaves of species of Salix, of which the male 

 had apparently not hitherto been observed. From 500 or 

 600 galls collected in 1875 he had obtained multitudes of fe- 

 males and two males; a similar result in 1876 had resulted 

 in one male. He was of opinion that by persevering from 

 season to season, it was possible to obtain the male of this 

 and of other allied species of which this sex is practically un- 

 known, though these might occur at rare intervals, the female 

 being capable of continuing the species without (of necessity) 

 immediate male influence. ^nt. Monthly Mag.^ Sept.^ 1876. 



AMERICAN FOSSIL INSECTS. 



A fossil cockroach and an earwig {Labidura) from South 

 Park, Colorado, is described by Mr. S. H. Scudder in the 

 Sixth Bulletin of the United States Geological Survey of the 

 Territories. 



THE AEMY WORM OF THE NORTH. 



A full account of this destructive caterpillar is given by 

 Mr. Riley in his "Eighth Annual Report on the Injurious 

 Insects of Missouri." It is very destructive to wheat and 

 other cereals and to grass. Living unnoticed until they 

 are more than half an inch in lens^th, thev beo-in to travel in 

 armies and devastate our fields early in August. Mr. Riley 

 has found that the females lay their eggs in strings of fifteen 

 or twenty along the inner base of the terminal blades where 

 they are yet doubled. The caterpillars hatch on the eighth 

 or tenth day after deposition, and they moult five times be- 

 fore turning to chrysalids. 



ADULT INSECTS WITH LARVAL HEADS. 



A curious research has been made by Dr. H. Hagen on a 

 butterfly {JSIorpho) from Brazil, which, though perfect in other 

 respects, had the head of the caterpillar instead of the butter- 

 fly's head. It seems that a few other examples of such de- 

 formities are known, viz. : four butterflies and seven moths, 

 three beetles and one fly. The presence of the head on the 

 winged adult seems due to the weakness of the caterpillar or 

 larva in casting the skin, that of the head becoming adherent 

 after that of the rest of the body has been thrown ofi". Me- 

 -moirs of the Mus. Comp. Zool.^ May^ 1876. 



