ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 573 



pores are found on the bases of all four wings, widely scattered on the 

 trochanter, and at the proximal ends of the femur and tibia of all six 

 legs, and generally distributed on the shaft and lancets of the sting. 

 Each pore is a chitinous structure connected with a bipolar sense-cell, 

 the peripheral end of which comes into direct contact with the external 

 air. 



Immature Stages of Tenthredinoidea.* — Alex. D. MacGillivray 

 gives a useful account of the details of the external ' characters of the 

 larvas of sawflies, and deals also with the varied modes of life and with 

 the cocoons. 



Life-history and Habits of Knapweed G-all-fly.t — J. T. Wads- 

 worth has studied Urophora solstitialis, a Trypetid fly, which lays its 

 eggs in the buds of the common weed Centaurea nigra, and thereby 

 reduces the number of seeds by about 50 p.c. The stimulus produced 

 by the presence of the larva in the embryonic tissue of the developing 

 ovule, and in the hypertrophied receptacle, induces a reaction of the 

 plant to form a structure that is possibly protective to the plant itself, 

 but which is also at the same time exactly suited to the requirements of 

 the fully-grown larva, forming as it does a very efficient means of pro- 

 tection during the prolonged period of hibernation. The egg-stage 

 lasts for eight to twelve days, about midsummer ; a feeding larval stage 

 lasts for three months, from July to October ; then follows a hibernat- 

 ing larval stage, from October to mid-May. The pupal stage lasts for 

 four or five weeks, from mid-May to the end of June. The flies emerge 

 from mid-June onwards, and probably live for about a month. All the 

 stages are carefully described, as also the long three-jointed ovipositor, 

 which is extended by pressure, presumably by muscular compression 

 acting on some of the body-fluids. 



Protective Coloration of Pupse of Pieris brassicse.J— L. F. 

 Hammond reports on some experiments which corroborate Prof. Poul- 

 ton's well-known results. The colour of the pupa approximates in a 

 considerable degree to that of its surroundings. The influence of the 

 colour of the surroundings is exerted on the larva. It affects the larva 

 during the third and fourth periods of its life— namely the period of rest 

 and the period between spinning up and the actual pupation. The 

 effect is greatest during the third period, and is brought about through 

 the nervous system. 



Gynandromorphous Lepidoptera.§ — E. A. Cockayne reports a 

 gynandromor phous specimen of Agriades coridon, predominantly female, 

 but with male hair scales and androconia on the smaller left side,' 

 and a gynandromorphous hybrid between Ithysia zonaria $ and Lycia 

 hirtaria 9 , resembling a female, but with the left antenna pectinated as 

 in the male. 



* Rep. Entomol. Soc. Ontario, No. 36 (1914) pp. 54-75 (1 pi.). 

 t Ann. Applied Bot., i. (1914) pp. 142-69 (2 pis. and 1 fig.). 

 X Proc. and Trans. Croydon Nat. Hist. Soc, viii. (1915) pp. 5-11. 

 § Proc. Entomol. Soc. London, 1915, pp. xv-xvi, in Trans. Entomol. Soc. 

 L ondon, 1915. 



