64 THE CAUSES WHICH PROPAGATE 



Butterflies are distinguished by antennae with a dilated 

 club-like termination, w^hich in the Skippers appears to pass into 

 the stout comb-like organs of the Sphinges ; and the Painted 

 Lady Butterfly, when its haustellum discovers no nectar in a 

 clover tube, may be observed to depx'ess the knob of an antenna 

 to the blossom. The plumy or pectinated antennae we see often 

 confined to the males of the silk-spinning moths ; and in the 

 Geometrina and night-fliers, where these brushes have de- 

 generated to mere pubescence, crenulation, or tufts, this character 

 yet exists, and must indicate some corresponding faculty. It is 

 evident, too, that as regards such kinds as the Gipsy Moth, 

 Vapourers, and Eggars, where the males carry the proudest 

 plumes, the feminine presence is not revealed by sight alone. 

 For when w^e expose a sedentary spinster of one of these with 

 not a speck visible in the sky, she fails not to draw her suitors 

 at the nuptial hour ; and then, as the eager male alights within 

 a few inches of his cynosure, he remains yet obtuse as regards 

 her presence ; for, moving round and round like a dog on the 

 scent, or a bee ejected from a pill-box, we often observe him 

 unconcernedly move of£ in the opposite direction, or even again 

 take wing. Nevertheless, to the human pituary membrane, with 

 some exception, as in the case of the Gipsy Moth, that on j)upa- 

 tion emits a piquant eflluvia of nitric acid, these insects and their 

 cocoons appear perfectly inodorous. The female lepidopteron 

 has also employment for her antenna in connection with repro- 

 duction. One dull afternoon, on the 4th September, during 

 the wet season of 1879, when migrating Painted Ladies and 

 Gamma Moths were swarming everywhere, my eye was arrested 

 by the pretty dappled wings of a female of the large Magpie, 

 then little less abundant in our country lanes, who was flying 

 most purposely from leaf to leaf along a hedgerow. She suc- 

 cessively visited a reddening bramble, a hawthorn, clematis, and 

 guelder rose, fruitlessly touching over their glandular surfaces 

 with a quick, alternate vibration of her black antennae, in search, 

 as I at first supposed, of honeydew. The crisping foliage of a 

 thorny sloe finally arrested her, and seemed to confer satisfac- 

 tion on her tactile perception ; for raising simultaneously her 

 feelers and crawling on to the centre of a leaf, she hung on at its 

 upper surface, elevated her wdngs, and by curling her abdomen 



