348 
ZOOLOGICAL LITlfill ATURE. 
cocoon. In winter the temperature of smooth larvae and pupae 
is nearly the same as that around them. Sometimes pupae 
differ in temperature under the same conditions, indicating 
variations in temperature during their development. In Bom- 
hyces the males are warmer than the females. In flying insects 
the heat is concentrated in the^ thorax, and increases in propor- 
tion to their powers of flight. This corresponds with the deve- 
lopment of the muscles. The heat increases in proportion to 
the exercise of normal activity. By introducing the tube of a 
very slender thermometer into the anus, Girard has been able 
to ascertain the internal temperature without violence. He is 
inclined to place insects, as a group styled “ animals with mixed 
temperature,^' between animals with constant temperature" 
(mammals and birds) and animals with variable temperature," 
or reptiles, amphibia, fish, and all invertebrata except insects. 
Girard also (Ann. Soc. Entom. Er. Se'ances, 1869, pp. 54-56) 
publishes a few observations on the temperature of the bodies 
of Lepidoptera and other insects, and (/. c. pp. 69, 70) some 
notes on the times of appearance and casual variation of various 
Lepidoptera. 
Goossens (Ann. Soc. Entom. France, Seances, 1869, pp. 60, 
61) has observed an organ between the head and first pair of 
legs in various larvae, Avhich he suggests may secrete a fluid 
which moistens their food. Goossens and Berce subsequently 
state (/. c. pp. 64-66) that the existence of this organ has already 
been recorded by Bonnet and Lacordaire, the former having de- 
voted two whole memoirs to the subject; Reaumur, to Avhom 
these observations were communicated, considered it to be an 
organ of prehension. 
L. Thouvelet states his opinion (Proc. Bost. Nat. Hist. Soc. 
xi. pp. 118-120) that the common occurrence of arrest of deve- 
lopment in one wing of a Lepidopterous insect is caused by the 
fluids from the abdomen rupturing the membrane of the wing 
during the process of expansion, either in consequence of some 
obstruction to the circulation, or of too dry an atmosphere. He 
also (/. c. pp. 136j 137) details the precautions necessary to be 
taken to obtain a union between two different species of Lepi- 
doptera. 
J. Hellins inquires whether the larvse of tliose Lepidoptera 
which pass the winter in the egg state are developed within the 
shell before or after hibernation. Ent. M. Mag. vi. p. 166. 
J. Jenneh Weik (Trans. Ent. Soc. Loud. 1869, pp. 21-26) 
details his experiments on insects Avhich are refused by birds. 
The images of Oryyia antiqua $ , Spilosoma mentbastri, An- 
thocera filipendulce, and of other brightly coloured day -flying 
moths, are either refused, or eaten with great hesitation. Hay- 
flying moths have usually brightly coloured uudcr-wings ; and 
Weir believes that birds generally seize these first, causing but 
