ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
673 
a. Insecta. 
Temperature Experiments on Lepidoptera.* — Mr. F. Merrifield lias 
continued liis experiments on tlie effects of temperature on Lepidoptera. 
These effects are different when applied at different periods of the pupal 
stage ; there may bo a great constitutional difference in sensitiveness to 
temperature between two seasonal emergences of the same species. In 
some, perhaps the most important, cases there is a reversion to some 
ancestral form, and here low temperatures produce one class of effects, 
and high temperatures a different class. The author is obviously correct 
in saying that the subject is one of much complication. 
Dr. F. A. Dixey j* discusses the bearing of these experiments] on 
theories of Heredity. 
Comparative Morphology of Abdomen of Lampyridse, Cantharidge, 
and Malachiidae.J — Hr. 0. Verhoeff has based his study on the abdo- 
minal segments, copulatory organs, ovipositors and dorsal glands of 
these families of Coleoptera ; and the essay is to be taken as a contri- 
bution to the phylogeny of the order, or class, as he calls it. He pro- 
poses a fresh classification, which will probably interest only the 
specialist, and concludes with some broader generalizations. 
He finds that the presence or absence of a basal plate may be charac- 
teristic of a whole order, as may also be an oviposition-apparatus of 
definite structure. The presence or absence and the form of certain 
plates of the segments may hold for a whole family. The presence or 
absence of stigmata on the eighth segment may be characteristic of 
orders. Whole families may have a penis of definite structure. The 
fusion of parameres with one another, and their form may be of essen- 
tially the same character in the representatives of families and sub- 
families ; a special type of preputial sac may be found in one subfamily. 
Definite endoskeletal structures may hold for orders, families, or sub- 
families. A definite differentiation or form of a basal plate may be 
typical for subfamilies. 
Absolute Force of Muscles.§— Prof. L. Camerano has made a large 
number of experiments on the flexor muscles of the mandibles of 
Coleoptera, determining their absolute force. It does not seem to vary 
much with the weight of the insect, at least the relative variations do 
not appear to show any regularity. But individual variations are 
frequent, and the left flexor may be stronger than the right, or that of 
the female may excel that of the male. The strength varies with the 
nature of the food. An average value is expressed by 3432*59 gr., a 
maximum at 6915*89 gr., while for Crustaceans the corresponding 
figures are 1841*21 and 3203, for the frog 2000 and 3000, for bivalves 
4545*79 and 12,431, and for man 7902 and 10,000. 
Male Reproductive Organs of Beetles.|] — Dr. K. Escherich de- 
scribes the genital system in the males of Cardbus, Blaps, and Hydro- 
9 Trans. Entomol. Soc. Lond., 1894, pp. 425-38 (1 pi.) ; tom. cit., pp. 439-46. 
t Tom. cit., pp. 439-46. 
j Arch. f. Naturg., lx. (1894) pp. 129-210 (4 pis.). 
§ Mem. R. Accaci. Sci. Torino, xliii. (1893) pp. 229-60. 
|| Zeitschr. f. wiss. Zool., lvii. (1894) pp. 620-41 (1 pi., 3 figs.). 
