174 



HARDWICKE'S SCIENCE-GOSSIP. 



[Atjg. 1, 1870. 



larger sea-weeds or zoophytes, or running over 

 stones or rocks (fig. 163). "When living, it is quite 

 smooth, but when dry the surface is minutely reti- 

 culated. Internally, when broken, the sponge- 

 masses are, for some time after being dead, of a 

 yellowish green. The membrane is abundantly 



Fig. 164. Spicules of Hulichondria panicea. 



spiculous, and the entire skeleton, as in other species 

 of the order, is made up of spicules cemented to- 

 gether. They are rather long and spindle-shaped, 

 somewhat curved, and pointed at either end (fig. 164). 

 It is recom mended that sections of all these sponges, 

 from the surface inwards, be mounted, instead of 

 the cleaned spicules ; by whicli means more of the 

 structure may be learnt. 



MOTH "SEMBL1NG." 



fPHE very capital paper by Mr. Wonfor, which 

 -*- has recently appeared in Science Gossip, 

 brings to my recollection sundry experiments of my 

 own in the same direction. I would note, first of 

 all, that the name given by the old collectors to this 

 peculiar method of attracting moths was doubtless 

 abbreviated from the word "assemble." And, in 

 some instances, the male individuals of a species 

 will assemble, under this fascinating power, in 

 goodly numbers, if the weather be favourable (for 

 this is an element in the matter which must not be 

 lost sight of), and the female moth, serving as the 

 bait, be recently emerged from the chrysalis. 

 Though Mr. Wonfor adduces some instances 

 wherein the attractive influence was shown after 

 a day or two, 1 believe these are exceptional cases, 

 and it is only now and then that a female will draw 

 a retinue of male admirers under such circum- 

 stances. I have not the slightest doubt myself 

 that the agency by which this is done is some 

 peculiar scent or aroma diffused through the air, 



and which, though almost infinitelyjarefied, is de- 

 tected, and, not only detected, but used as a means 

 of guidance by the male moths. I have perceived 

 an odour given off from some species of Arctia, 

 and also by 0. gonbstigma (Scarce Vapourer), slight 

 indeed, but sufficiently noticeable by the average 

 human organ of smell, and, no doubt, better recog- 

 nized by the finer organs of a moth, and apparently 

 at a considerable distance off. There are those, it 

 should be stated, who believe that this attraction is 

 induced, not by the faculty of smell, but by some 

 peculiar sense unknown to us at present. This, 

 however, is mere theory, while the other view ap- 

 pears to rest upon actual fact. 



Eailure in some cases where females have been 

 taken out to " semble " males, has been caused by 

 the circumstance hinted at by Mr. Wonfor, namely, 

 that the hour was one not usually chosen by the 

 species as its time of flight. Some constantly ad- 

 here to a particular time, and will not stir under 

 any persuasive agency which may be employed by 

 the female individuals thus experimented with. 

 And there are also certain species even amongst the 

 Bombycina group of moths, where the males are 

 too shy to approach while any observer of the human 

 race is in near proximity. In such cases it has been 

 recommended, when you have a virgin female moth 

 to dispose of, to secure her to a branch or twig by 

 a silken thread, when, if you fail to catch male 

 moths, you will at least get the female impregnated, 

 and have a hatch of eggs from which you may breed 

 males. I have recently tried this with the Pale 

 Tussock and the Coxcomb Prominent, but did not 

 succeed in either case in getting eggs from them ; 

 the cause being, I think, that through the pupa; 

 having been kept in confinement they emerged 

 rather too soon, and anticipated the flight of the 

 species at large. It is not a very easy matter, how- 

 ever, to pass a band first round the body of a living 

 moth, and tiien secure it in a suitable position to 

 some twig. I suggest, as an improvement, which I 

 shall certainly try in future experiments of the kind, 

 that it would be well to submit the moth first to a 

 process of anasthesia, just 'producing that slight 

 insensibility which will pass off, in most species, in 

 the course of an hour, or even less, leaving the 

 individual none the worse. 



I do not think that much success in this direction 

 can be anticipated amongst the Hawk-moth tribe, 

 llennie mentions an experiment of the kind which 

 he tried with the Lime Hawk, when he exposed a 

 female for some days in a locality which he knew to 

 yield the species. Yet some of the Hawk-moths 

 will pair in confinement, as for instance the Poplar 

 and the Eyed Hawk. But I believe that these 

 species, which, as we know, are in the habit of re- 

 sorting to flowers, take some food usually ere they 

 pair ; also the females of some I have captured on 

 the wing have subsequently laid eggs which prove 



