ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 647 



A much greater degree of constancy is manifested by tlie Apidae ; and 

 this becomes all but absolute in the hive-bee. It is an interesting 

 circumstance that this constancy appears to increase in proportion 

 to the part performed by the insects in carrying pollen from flower 

 to flower. A much larger number of observations is, however, needed 

 in order to determine with certainty any general law, and especially 

 a careful microscopic examination of the pollen attached to the pro- 

 boscis, mandibles, legs, and under side of the abdomen and thorax. 

 As respects preference for particular colours, the Lepidoptera paid, 

 while under observation, 70 visits to red or pink flowers, 5 to blue, 

 15 to yellow, 5 to white ; the Diptera, 9 to red or pink, 8 to yellow, 

 20 to white; the Hymenoptera, 203 to red or pink, 126 to blue, 11 to 

 yellow, 17 to white. 



E. M. Christy also records* in detail the movements of 76 

 insects while engaged in visiting 2400 flowers. He tabulates the 

 results, and concludes that insects do possess a decided preference for 

 a number of successive visits to the same species of flower, although 

 this is not invariably the case. Most of the observations were made 

 on bees, which seem to perform the fertilization of at least one-half 

 of all the flowers fertilized by insects in this country. Butterflies, as 

 a rule, seem to wander purposelessly in their flight; nevertheless 

 some species, including the Fritillaries, are fairly methodic. The 

 author believes that it is not by colour alone that insects are guided 

 from one flower to another of the same species, and the sense of 

 smell is suggested. Bees, he avers, have but poor sight for long 

 distances, but good sight for short distances ; of 55 humble bees 

 watched, 26 visited blue flowers, 12 of the bees were methodic in their 

 visits and 5 not so ; 13 visited white flowers, 5 were methodic and 8 not 

 at all ; 11 visited yellow flowers, of which 5 were methodic and 6 not ; 

 28 visited red flowers, 7 were methodic, 9 nearly so, while 12 were not. 

 Mr. Christy inclines to the opinion (though admitting paucity of 

 data) that bees, in a flight from their nest, confine their visits 

 exclusively or principally to one species of plant. 



Rudimentary Wings in the Coleoptera.t— Dr. H. Dewitz points 

 out that the hind-wings of the Coleoptera show most distinctly how an 

 organ may gradually become aborted by disuse, and how a transfor- 

 mation of the whole habit of the animal may be connected with this. 

 The membranous hind- wings of beetles, which serve for flight, lie, as 

 is well known, concealed beneath the firm horny fore-wings, the so- 

 called elytra. For the purpose of flight the elytra are raised, and the 

 folded hind- wings extended, so as often to exceed the former in length. 

 But many beetles do not fly at all. In these we find the hind wings 

 more or less aborted or entirely deficient. This phenomenon occurs 

 with especial frequency among the Carabidae, Melasomata, and Curcu- 

 lionidae, and also, although less frequently, among the Ptinidae. 



As the wings are already indicated in the larva. Dr. Dewitz was 

 inclined to think that, in one or other of the species entirely destitute 



* Journ. Linn. Soc. (Zool.) xvii (1883) pp. 186-94. 



t Zool. Anzeig., vi. (1883) p. 315. Ann. and Mag. Nat. Hist., xii. (1883) 

 pp. 108-11. 



