ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 553 



Genital Appendag-es in Blue Butterflies.* — T. A. Chapman describes 

 with great wealth of ilhtstration the male and female appendages in 

 the tribe Plebeiidi of " Blues " (Lycajninffi). He devotes particular 

 attention to the correlation of the two sets of parts in pairing. 



Colour of Cocoons in Philosamia.f — Onera A. Merritt Hawkes has 

 studied the effect of moisture upon the silk of the hybrid Philosamia 

 {Attacus) ricini $ and P. cynthia 9 • The wild forms of P. ricini have 

 a pure white cocoon ; the domesticated form has cocoons sometimes pale 

 fawn, sometimes white. Those experimented with produced white 

 cocoons. In P. cynthia the colour of the cocoon is typically red-brown, 

 varying in intensity. 



The larvffi of the hybrid moths may begin to spin with a white or 

 a fawn silk. In all but two cases the white or fawn cocoons became 

 various shades of red-brown when placed in a very moist atmosphere. 

 This change can occur when the silk is removed from the cocoon, and is 

 due to the effect of water vapour and not to atmospheric oxygen. No 

 evidence indicated that the coloration is due to any excretion of the 

 larva, and there is some negative evidence suggesting that excretion has 

 no influence at all. Further research is needed to ascertain the chemical 

 differences between brown and white silk. Further breeding is necessary 

 to discover the causes to which the variations are due. 



Pink Coloration in Katydid. J — Hancock finds that when a pink 

 female of AmhJycorypha obJongifolia is crossed with a normal green male 

 some of the hybrid progeny emerged after two years, others after three, 

 and that nine were pink, four greeu. The sexes were about evenly 

 divided in both the pink and the green forms. The F2 generation has 

 not yet appeared. 



Respiration in Aquatic Insects. § — Frank Brochet adds to previous 

 studies on aquatic insects an account of some experiments on Dytlscvs 

 and HydropliHus. He finds that inspiration is active, and is due to a 

 lateral contraction of the metathorax. Expiration is active, and is due 

 to a dorso-ventral flattening of the metathorax. It is probable that, 

 apart from the muscular action, the elasticity of the wall of the meta- 

 thorax assists in respiration. The integument tends to resume its 

 normal form, intermediate between that during expiration and that 

 during inspiration. It is probable that most of the abdominal move- 

 ments are only secondarily and distantly connected with respiration. A 

 full account is given of the musculature. 



to" 



Notes on Indian Insects.|| — T. Bainbridge Fletcher communicates 

 a hundred notes on Indian insects. An incipient nest of an ant, 



* Trans. Entomol. Soc. London, 1910, pp. 156-80 [ib pis.). 

 t Journ. Exper. ZooL, sxi. (1916) pp. 51-60. 



X Entom. News, xxvii. (1916) pp. 70-82. See also Trans. Amer. Micr. S( c, 

 XXXV. (1916) p. 73. 



§ Rev. Suisse Zool., xxiii. (1916) pp. 401-38 (1 pi.). 



II Bull. No. 59, Agric. Research Inst. Pusa, 1916, pp. 1-39 (20 figs.). 



Dec. 20th, 1916 2 q 



