1897.] Entomology. 451 
pediculids, mallophagids, hippoboscids, and sarcoptids. In other cases 
the same effect is attained by a different process, as the flattening of the 
body vertically in fleas and horizontally in most other permanent para- 
sites. Modifications of the mouth-parts, eyes, and antennz are very 
great, and furnish most striking examples of the modification of struc- 
tures for the adaptation to special conditions. 
Life-History of Coleophora malivorella.—In an admirable 
Bulletin (124 of Cornell Experiment Station), Mr. M. V. Slingerland 
discusses the Pistol Case-bearer, summarizing its life-history thus: 
The insect spends about seven months (from September Ist to April Ist) 
of its life in hibernation as a minute, half-grown caterpillar in a small 
pistol-shaped case attached to a twig. In the spring the caterpillars 
attack the swelling buds, the expanding leaves, and especially the 
flowers. About May Ist the cases are fastened to the twigs, where they 
remain for four days, during which time the caterpillars shed their 
skin or moult. They do not make any complete new suit as they grow, 
but are content with making additions to the ends and side of the old 
suit. They are not miners, but feed openly, eating irregular holes in 
the leaves, often skeletonizing them. They are most destructive on the 
flowers, where they eat the petals and stems. In the latter part of May 
they cease feeding, securely fasten the cases to the branches, and in 
about two weeks change to pupæ within. The moth emerges in two or 
three weeks, and soon glues its minute, pretty, cinnamon-colored, in- 
verted cup-like eggs to the surfaces of the leaves. The egg-stage lasts 
about a week, the little caterpillar emerging about July 22d. They 
begin eating little holes in the leaves, and during their first meal con- 
struct of silk and excrement a small case or suit for themselves. They 
continue feeding on the leaves, adding to their suits from time to time, 
until about September 1st, when they begin to migrate to the twigs, and 
there fasten their little pistol-shaped cases to the bark. The winter is 
passed in these snug, warm, secure quarters. 
Studies of Mimicry.—Col. C. Swinhoe, after studying and think- 
ing over the general theory of protective mimicry, conceived that the 
subject should be advanced by the study of a small group of widespread 
mimetic species throughout the different countries included in its range. 
While the Bolina group of Hypolimnas contains according to system- 
atists a number of species, they can all be merged into two, and it was 
these that he selected for his purpose. He describes in detail the ap- 
pearances of these widely spread forms, and comes to the conclusion 
that the facts afford the strongest support to the theory of mimicry as 
