138 COHRESPONDENCE, 



Is THE Akfm an IxsEC'TivoROtTS Plant ? — Tliis euquiry ia made at 

 page 106, where the fact is recorded that in numerous speciuieus of 

 Arum m((ci(Iatum examined last summer by the \\Titer of tlie question 

 small insects and chitinous fi'agments of others were invariably found 

 inside the nearly closed spathes. The followdng obsei-vatious may, 

 perhaps, throw Sonne hght on the subject. For two years past I have 

 growTi a plant of Arum criiiitum in my garden, and each year it has 

 produced one of its lugubrious looking spathes. The plant grows about 

 18in. high. The spathe is very lai'ge, the spadix long and strange 

 looking. The inside of the spathe and the whole of the visible part of 

 the spadix are covered thicldy %vith black hau's. "^Ticn the infloresence 

 is fully developed a most offensive camon-like smell is emitted. Directly 

 the disagi-eeable odotir is produced blue bottle flies ( Mu^ca vomitoria) 

 make their appearance and swarm on to the protruding lip of the spathe. 

 Both years I have noticed no sign of these flies until the fetid smell of 

 the Arum attracted them. Readers of Robert BrowTiing's weird poem 

 of the Pied Piper of Hamelin will remember how mysteriously the 

 children were compelled to follow the insulted musician : the flics seem 

 as strangely and powerfully fascinated by the Ai-um. They arrive in a 

 bustle, they have evidently come purposely, they fly tinen-ingly to the 

 plant, they then speedily make their way to the narrow entrance to the 

 lower part of the spathe in which the base of the spadix is chambered 

 in almost absolute darkness. The inlet is narrow, and is well protected 

 by the hairs before mentioned, though they seem no obstacle to the 

 ingress of the flies. But after they are once inside there they must 

 remain ; whether stupefied by the noxious exhalation of the plant or 

 imprisoned by the hairs which yielded them sxich easy entrance I do not 

 know. I have watched the plant for hours, but never saw a fly return 

 from what may be deemed a condemned cell. The spathe remains open 

 only a day or two at most, and then gradually closes and shrivels up. 

 Each year at an interval of a week or so after the closing of the spathe I 

 have cut open the chambered part of it, and have found it nearly full of 

 dead and partially decomposed flies. If I am fortunate enough to have 

 the plant in flower this summer I shall take care to obsei've it more 

 closely, and wiU forward it to Mr. Lawson Tait for examination. — 

 E. W. B., Moseley. 



Wasted Energy. — There are many hard-working Naturalists in the 

 Yorkshire Union, and no doubt in the Midland too, whose energies are 

 more or less wasted. Speaking of Entomologists particularly, too many 

 devote all their attention to one family. Thus Lepidoptera are generally 

 the insects most systematically collected, and there are instances of all 

 the Entomologists in a society collecting nothing else. The result is a 

 waste of energy, as half the number would generally work a district effi- 

 ciently ; whereas the larger number overdo it, and frequently exterminate 

 the rarer insects. Where so many are engaged in the same pursuit there 

 is sure to be rivalry as to who shall make the largest collection. Thus it 

 comes to pass that a dozen or more specimens are obtained where two 

 would serve evei'y legitimate purpose. One male and one female with 

 varieties are enough images for any scientific collection. To these 

 should be added specimens of their various stages of metamorphosis. 

 Lai*va-preserving ia now so generally well understood that neai-ly all 

 Lepidopterists can presence laiwee (most kinds at all events) as well 

 as they can set insects. These should invariably bo mounted on a 

 twig or leaf of the plant on which they ordinarily feed. The pupa and its 

 cocoon (especially in the case of the Bombycidtp) should, where possible, 

 always form part of the collection. But tJaoro are other fields where the 

 enei-gies of the EntomologisL may find ample and useful employment, 

 and whore at present the workers are far too few. Take, for instance, 

 tho DijJtera : how little ia done with them, and yet how much wants 



