ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
339 
darkness, while a high temperature has the opposite effect. In the 
species operated upon a difference between 80° and 57° is sufficient to 
produce the extreme variation in darkness caused by temperature. 
Dryness or moisture during the pupal period had little or no effect on 
the species used. If Prof. Weismann’s theory that most existing 
Lepidoptera in Europe and North America have come to us from 
glacial times or climates is correct, icing the pupae might assist us in 
tracing their evolution. 
Larvae of British Butterflies and Moths.* — Mr. H. T. Stainton has 
produced the fourth volume of the late Mr. William Buckler’s account 
of the British Lepidoptera. In this volume part of the night-flying 
moths (Noctuae) are described and figured in great wealth of detail. 
Mistake of a Butterfly. | — Dr. R. Blanchard reports that one morning 
at 8*30 he saw a Sphinx fly into a deeply shaded room and examine the 
flowers on the carpet of the floor. Finding no success it tried those on 
the wall, and returned to the floor. The author was struck with the 
way in which the visitor avoided the representations of foliage, and he 
points out that this strange visit shows that the ordinary explanation 
that crepuscular plants are visited because of their odour is not com- 
pletely satisfactory. 
The Stinging Apparatus in Formica.* — Dr. 0. W. Beyer maintains 
that the stinging apparatus in Formica is a retrogressive modification of 
that possessed by Apis, Vespa , Myrmica, and other Hymenoptera. He 
bases his argument on a solid foundation, for he traces the development 
of the apparatus through eighteen stages in Apis mellifica , through fifteen 
in Vespa vulgaris , through eleven in Myrmica Isevinodis , through eleven 
in Formica rufa. In all four, the essential parts of the apparatus, their 
arrangement and their relation to the surface of the body, and the suc- 
cession of developmental stages are the same. From among the interest- 
ing facts which Dr. Beyer brings forward to show that the apparatus in 
question is retrogressive, not progressive, we may cite the correlation 
between the poison-gland and the sting. In Apis the sting is most com- 
plicated, the gland is simplest ; in Formica the sting is reduced, the 
gland is very large ; the other two genera, Vespa and Myrmica, are pre- 
cisely intermediate. It seems most plausible that in the ancestors of 
Formica the sting ceased, for some unknown reason, to be very effective ; 
there was the more need for abundant poison, and the gland grew ; the 
muscles of the sting degenerated, those of the poison reservoir and the 
duct increased in strength. 
Structure and Life-history of Encyrtus fuscicollis.§ — M. E. 
Bugnion describes this minute Chalcidian, which is parasitic within 
caterpillars, e. g. those of Hyponomeuta cognatella. In the abdominal 
cavity of the caterpillars ho found a closed tube, inclosing the embryos 
and also the nutritive substance on which the larvae feed. This tube 
seems to be formed by the ova themselves. The larva has an anus, 
though this is said to be absent in other entomophagous forms. When 
* London, printed for the Ray Society, 8vo, 116 pp., pis. liv.-lxix. 
f Bull. Soc. Zool. France, xvi. (1891) pp. 23-4. 
X Jenaische Zeitschr. Naturwiss, xxv. (1890) pp. 26-112 (2 pis.). 
§ Rec. Zoo). Suisse, v. (1890) pp. 435-70 (2 pis.). 
