Darwin Correspondence Project

Rock Island. Illinois U.S.

Aug. 29 1868

Chas. Darwin Esq.

My dear Sir,

I have been waiting & waiting, day after day & month after month, expecting to receive the copy of your new book which you were so kind as to order sent to me. Finally I wrote to Baillière Bros. of New York, to enquire whether they knew anything of it; & on July 28 they answered that no book for me had been received, but that ``when they next wrote to London they would make enquiries about it.'' Since then I have heard nothing further from them. Now, whether John Murray failed to send the book according to your order, or whether the London Baillières have received it but failed to forward it to New York, or whether the New York Baillierès have received it but failed to forward it to me, I do not know. It does certainly seem singular, that on two separate occasions so simple a thing as sending a book from London to New York should involve so much trouble & delay.

If I had known how this matter was going to turn out, I should have bought a copy of the American edition long ago. As it is, I have within the last week had the opportunity of borrowing a copy of that edition & am perusing it with great delight. What an enormous amount of interesting & instructive facts you have accumulated & how skilfully you have arranged them!

I have recently returned like a dog to his vomit, & again become Editor of a Monthly Periodical (of which I enclose a Prospectus) devoted to Economic Entomology. I think this time we shall make it a success; at all events I hope & expect it, which is more than I ever did as regards the old ``Practical Entomologist'', from the total lack of business talent & tact in the Society that published it. By the way, my partner in this enterprise—C. V. Riley—who is an active energetic young man of 25, without any very deep scientific knowledge, but an excellent hand at breeding insects, & what is most important of all a first-rate entomological draughtsman, is very desirous to get your photograph, & also, if possible, that of Westwood. Can you assist in gratifying his wishes? If so, you will be conferring a great favor upon me. He has recently been appointed State Entomologist of Missouri, with a salary of $2500 per annum; has written a good deal on entomological matters for the Agricultural Press; & not long ago published in the Prairie Farmer a tolerably good review of your book. At his request, I enclose for your eye a paragraph of his composition on the half-peach half-nectarine question. I was not previously aware that anybody had supposed that the peach & the nectarine were distinct creations; but as I now find the fact asserted in type, (& you, too, say the same thing,) I suppose I must believe it. ``An honest man & of good judgement'', says Rabelais, ``believeth still what is told him, & that which he finds written.''

I have been so busy all the summer with my professional duties, & with getting the ``American Entomologist'' well under way, that I have had no time to make any observations on the stridulation of insects. On July 22nd., however, I wrote to Dr. LeConte, who I rather think has paid special attention to the stridulatory organs of Coleoptera, requesting him to furnish you with any information on the subject that he could. As ill luck would have it, he has been staying at a watering-place all summer for the benefit of his wife's health, & has not yet, as I hear from him, received or opened my letter, which, as it contained an enclosure of insects, was by his orders retained at his town house. He will not return home till Sept. 20th., when I hope he will attend to my request.

Taking my opinion for what it is worth (& that is but little, for I have never specially studied the subject) I believe that in Coleoptera generally, perhaps universally, stridulation is a means of defense to both sexes alike & not a sexual call. Of course with the Cicada & also the Crickets and Grasshoppers we all know that stridulation is sexual, & usually confined exclusively to the males, though I have noticed that our female Catydid (Platyphyllum concavum Harris) makes a feeble grating noise by shuffling together, when captured, the base of her elytra. In this species the male has the usual glassy drum at the base of its elytra, while the female has nothing of the kind & is considered by author<s> as dumb, or ``silent'' as Harris phrases it. In case you are disposed to investigate this matter more closely, I mail herewith a copy of a recent Paper on Orthopterous Stridulation by Scudder; also a copy of a Paper on our Deer & Elk by Judge Caton, which I requested him to send me for you, & which I think you will find very good. Please return Scudder at your leisure; Caton of course you can keep. Caton wd. highly appreciate a line of acknowledgement from you. His address is ``Hon. Judge Caton, Ottawa, Ill. U.S.''

As to the stridulation of the Lamellicorns, I find that LeConte makes the following remarks in his Introduction &c:—``Coprinic Organs of stridulation are found on the dorsal surface of the abdomen of certain species.'' (p. 124.) ``Trogini. The genus Trox possesses a distinct stridulating organ. It is an elliptical plate, with pearly reflections, occupying the upper part of the external face of the ascending portion of the first ventral segment, & is covered by the elytra. On the inner surface of the elytra, near the margin, about opposite the metathorax, is an oval smooth polished space, which has probably some connection with the stridulating organ.'' (p. 131.) ``Dynastini. Organs of stridulation are found in many genera. They consist of rugose spaces, usually on the propygidium (G. Oryctes), sometimes on the inner surface of the elytra. (GG. Ligyrus & Phileurus.)'' p. 143. Although LeConte always states the sexual characters very fully and carefully, yet he nowhere asserts or implies that in any Lamellicorns the stridulating organs differ in the sexes. Observe that in the same tribe, Dynastini, these organs are differently located in different genera. I do not think our N.A. Geotrupini stridulate. Certainly LeConte is silent on that point.

Riley & myself have recently been working out the geographical distribution of the so-called Seventeen-year Locust, (Cicada septemdecim L.), the larva of which, as you are probably aware, lives underground just 17-years. He has the merit of being the first entomologist to publish the now undoubted fact, that, besides the 17-year brood, there is a very extensive brood which comes out in definite localities every 13 years (not 17 years). After satisfying myself of this scientifically new & singular fact, (at first, as is my nature, I did not believe it,) I told him that I was sure that the 17-year & the 13-year forms must be distinct species; for otherwise we should have 16-year forms, 15-year forms &c &c, which is not the case. Yet, on the closest external comparison, the two forms are undistinguishable by any constant character. At last Dr. Hagen—who with his lady was staying at my house after a Scientific Meeting at Chicago—took the matter in hand, having formerly published a Monograph of European Cicadæ & ascertained that with them the sexual ♂ organs differ often in different species. Well, he & I together, on examining in my office 4 ♂, found that the genital hook in the 17-year brood is shaped thus

[DIAG HERE]

In all other respects but this genital hooklet, the two species are absolutely identical. They are, with this single exception, as like as two peas. After personally comparing the two, I cannot see how any sane man can infer that each was separately created. Yet they must be distinct species now, (according to my interpretation or definition of that term) for otherwise they would intercross & produce races having intermediate genital hooklets and intermediate periodic times, 16 years, 15 years &c  You will object, perhaps, that coming out in different years septemdecim & tredecim have no chance to intercross. Yes, they have! This very year a large brood of tredecim came out in North & Central Penna. & simultaneously in Central & South Penna a large brood of septemdecim. But I am riding my hobby to death.

Yours ever, Benj. D. Walsh

P.S. I really must bore you with the additional remark, that the tredecim seems to have been derived from the septemdecim & not the reverse, for the following reason:—Where tredecim prevails, it is very often the case that a small brood appears in the preceding or succeeding year to the regular periodic time. (We can trace back the regular brood over a large extent of country by the most indisputable evidence to A.D. 1829, 1842, 1855 & 1868.) Now, this does not seem to be the case with septemdecim, or at all events but very rarely. Hence I infer that tredecim is a sort of incipient species, which has not yet settled down into a perfectly regular periodic time. By heating up with flues the whole side of a hill for horticultural purposes, Dr. Hull of Alton, Illinois (a most excellent observer) caused tredecim to come out in March instead of the end of May, & so on through April & May, in regular succession, as the heat of the flues was applied from month to month. What is a most singular & inexplicable fact, the ♂ Cicada, thus artificially forced like early asparagus, were totally dumb!! What do you make of that fact?

According to my latest revision, there exist in the U.S. ten distinct broods of septemdecim coming out at different periodic times, & two distinct broods of tredecim coming out also at different periodic times. In both cases, each brood covers a definite area of country, which we propose to represent to the eye by a ``Locust map'' of the U.S. ``Ohe, jam satis!''