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138
Correspondence.

Is the Arum Insectivorous Plant?—This enquiry is made at page 100, where the fact is recorded that in numerous specimens of Arum maculatum examined last summer by the writer of the question small insects and chitinous fragments of others were invariably found inside the nearly closed spathes. The following observations may, perhaps, throw some light on the subject. For two years past} have grown a plant of Arum crinitum in my garden, and each year if has produced one of its lugubrious locking spathes. The plant grows about 18in. high. The spathe is vary large, the spadix long and strange looking. The inside of the spathe and the whole of the visible part of the spadix are covered thickly with black hairs. When the inflorescence is fully developed most offensive carrion-like smell is emitted, Directly the disagreeable odour is produced blue bottle flies (Musca romiteria) 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 Browning's weird poem of the Pied Piper of Hamelin will remember bow mysteriously the children were compelled to follow the insulted musician: the flies seem as strangely and powerfully fascinated by the Arum, They arrive in a bustle, they have evidently come purposely, they fly unerringly to the plant, they then speedily make their wav 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 seam 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 such easy entrances 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 observe it more closely, and will 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, whoso 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 efficiently; 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 every legitimate purpose. One male and one female with varieties are enough imagos for any scientific collection. To those should be added specimens of their various stages of metamorphosis. Larva-preserving is now so generally well understood that nearly all Lepidopterists can preserve larvæ (most kinds at all events) as well as they can set insects. Those should invariably be mounted on a twig or leaf of the plant on which they ordinarily feed. The pupa and its cocoon (especially in the ease of the Bombveidæ) should, where possible, always form part of the collection. But there are other fields where the energies of the Entomologist may find ample and useful employment, and where at present, the workers are far too few. Take, for instance, the Diptera: how little is done with them, and yet how much wants