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Darwin Correspondence Project

From J. T. Moggridge   [before 22] June 18711

8 Park Hill | Queen’s Road | Richmond | (Surrey)

June | 1871

My dear Sir

The other day I mentioned to Mr. Alfred Wallace, in the course of conversation, that I have casually made a few observations on the nature of the objects which Ants at Mentone collect & carry to their nests, & he expressed an opinion that these notes, imperfect & incomplete as they are, might interest you.—2

I had myself supposed that the habits of ants, forming as they do so very attractive a subject for investigation, had long ago been almost exhaustively described, but this Mr. Wallace believes to be by no means the case.— —

When sitting out of doors at Mentone, & I spend a great part of almost every day thus,—I remarked that ants carry a great variety of objects, & that of these seeds form in many cases a very large proportion, & it at once occurred to me that we have here an additional agency for the transport of seeds from place to place; as not only may each individual ant carry seeds for a considerable distance, but the number of colonies of ants throughout the south is so great that, if all were seed collectors, one might almost conceive of a plant passing its seeds from one set of carriers to another along the whole line from Marseilles to Genoa, or even to Constantinople!.—

However, without claiming for ants any such extravagant pretensions, I have convinced myself that certain species do store large quantities of seed, & that in a methodical manner.

I have observed, by mere chance, two cases in which on one side of the mouth of a subterranean nest of ants of medium size (black in one case), there was piled up a semicircular heap of what appeared to be rubbish, measuring about 6 inches in length and 2 or 3 in depth—

On examination these heaps proved to consist of empty capsules & glumes of grass along with a few grains of gravel, small land-shells & bits of stick.

On the top of the heap in one case I found some capsules containing seeds which had recently been deposited there by the incoming train of ants, & not yet taken inside the nest by the other set of workers— —

During April last at Mentone I was able to watch a great part of this interesting harvest-home.—

The nest with its rubbish heap or ‘kitchen midden’ was placed in the soft sandstone-grit rock, on a warm slope, & from this point an outgoing & incoming train of ants reached as far as a lemon terrace covered with weeds at about 10 paces distant.—

I was anxious to see how the ants managed to sever the fruits, which they were for the most part carrying entire, from the main stem, more especially as they gathered the capsules green, in order to avoid, as I suppose, the shedding of the seeds.— After a short time I saw an ant ascend the stem of a fruiting plant of Capsella Bursa-pastoris Dc.,3 & select a well-filled but green silicle about mid way up—

At first it tried to tear the fruit off, dragging it in a downwards direction; & finding the fibre too tough to yield thus it called in the assistance of another ant, which had by this time climbed up the stem, when both together tried in vain to drag it off.—

Then the new comer seemed to address himself to his fellow-workman & tell him to go about his business & leave the job to him; & no sooner was his command obeyed than he again seized the silicle in his jaws, &, fixing his hind legs as a pivot contrived to turn the the fruit round & round so that the peduncle became more & more twisted, & at length the fibres snapped.—

It then descended the stem, patiently backing & turning upwards again as often as it’s clumsy burden became wedged between the thickly-set peduncles, & joined the line of his companions on their return to the nest—

As soon as the workers reached the entrance of their home they deposited their burdens on or near the heap & returned at once to work.— Then from inside the nest other workers come up & carry down the newly brought material, while others again appear, bringing up from below the refuse, empty capsules, grains of sand, bits of twigs & rubbish generally which they deposit on the kitchen-midden.

Underground there must be a committee sitting who determine what to keep & what to reject, & this is necessary, for the labourers are not always as wise in selecting as they are patient in securing their materials.

I carried away as a sample about one third of an envelope-full of the refuse, taking pinches at hazard from the heap—

This on examination proved to contain the following materials:—. Seeds of Amaranthus; seeds and capsules of Stellaria media Vill.; seeds & silicles of Arabis Thaliana4 L.; Fumaria pods, one empty the others intact; seeds & empty capsules of Fumana viscida5 Spach; portions of carpophore & base of calyx of Geranium; spikelets of Andropogon Ischæmum6 L. & two other grasses; achenes of wild Marigold (Calendula arvensis L.); one pod of Alyssum Maritimum7 L.; flowers of Linaria simplex DC.; pappus of Composite; portions of leaves of a grass; scales from male inflorescence of Pinus; a thorn of Cytisus Spinosus;8 fragments of twigs; silk case, 8mm. long, of larva of one of the Tineina; grains of grit; dropping of bird.—

Among all these objects the capsules, usually empty, of Stellaria media Vill. were most abundant, & after these the fruits of Capsella, Arabis, Geranium & Fumaria

A similar heap observed at Cannes was composed as follows:— Spikelets, in one case at least containing grain, of three species (or four) of Grasses; Capsules, almost all empty of Veronica (the remains of Grasses & Veronica constituted the bulk of the heap); calyces of Fumana; calyx of Calamintha?; seeds of two species which I do not recognise; a few small land-shells; fragments of grit; portions of twigs & leaves.—

This kitchen-midden was observed in May, & it seems probable that, in both this case & that described at Mentone, the ants were making their store against the parched-up summer time, when the leaves of the shore plants shrivel up & the native vegetation rests with few exceptions—

In order to ascertain the nature of the objects which ants habitually carry, I have on several occasions stopped ants forming parts of trains carrying burdens & noted the materials of which I robbed them— The following were the results obtained on two occasions:—

1. Fourteen ants, each carrying a single burden, were thus robbed by me of— 1 head of Beetle; 1 abdomen and thorax of dipterous insect; 7 grains of two species of grasses (Setaria9 and —?) enclosed in the glumes; 1 ripe carpel with awn adhering of Erodium; 4 achenes of Platanus orientalis.—10

2. Eleven ants, robbed by me of:— 5 grains of Setaria & one of Avena, enclosed in their glumes; two petals of Cistus; Capsule and portion of stem with pair of leaves of Veronica         ; tuft of hairs, like those of pappus in Composites, with vegetable fibre adhering; splinter of rotten wood; several small grains of mica and grit.

In cases 1 and 2 the ants were bearing their prizes to nests below ground, without kitchen middens near the mouth.—

Now I have frequently observed that ants are easily frightened & that they then drop their burdens, which they afterwards search about vainly for & at length abandon.— In this way seeds may frequently be deposited in places where they can germinate; the nests of ants in which are stores of seeds are also at times abandoned, & besides this each kitchen midden contains, along with a great mass of rubbish, many good seeds, as I have myself proved.—

A seed thus sowed may, if it come to maturity, scatter hundreds of seeds in the following season ready to be carried in many directions by other colonies of ants, & other recognised agents of dispersal; & if of these seeds 10 be safely planted & reared & 10 again from each of these, thanks to the unconscious assistance of ants, we may imagine a progressive multiplication which if unchecked would suffice to cover all ant-inhabited countries within a very short space of time.— I intend next season to make further observations on the kitchen-midden-ants, & to collect specimens of the insects themselves should the habit prove to have passed hitherto unobserved in Europe.— — —

I hope from what I hear that you have passed a tolerable winter, & are on the whole better. I spent a pleasant winter at Mentone, & am certainly rather stronger than I have been since my illness in 1869.—

I have continued my observations on Arbutus; Ophrys insectifera L.;11 Viola odorata L., & two species split by M. Jordan from V. tricolor cultivated by seed;12 Narcissus Tazetta L., & a species of Clypeola split by Jordan from C. Jonthlaspi.—13

I hope next winter to turn the greater part of my attention to sorting my notes on these plants, & to renew my observations & improve them, as I am now at work upon the 4th. part of my Flora, concluding the series.—14

One of many interesting little discoveries that I have made is that Ophrys insectifera L. is occasionally capable of multiplying itself by producing an extra bud and tuber! This is a rare occurrence, so rare as to be properly called abnormal, but one which one might conceive of being of high importance to the individual.—

I had always hitherto believed, in common with the rest of the botanical world, that this plant is only multiplied by seed!— —

Will you present my compliments to Mrs. Darwin, & believe me | Yrs. very sincerely | J. Traherne Moggridge.

Footnotes

The date is established by the relationship between this letter and the letter to J. T. Moggridge, 22 June [1871].
Moggridge refers to Alfred Russel Wallace. Owing to chronic ill health, Moggridge spent most winters at Mentone (now Menton), a town on the French Riviera near the Italian border (R. Desmond 1994).
Capsella bursa-pastoris is shepherd’s purse, so named because of its small triangular silicles or pods.
Arabis thaliana is now Arabidopsis thaliana (mouse-eared cress).
Fumana viscida is now F. thymifolia (thyme-leaved fumana).
Andropogon ischaemum is now Bothriochloa ischaemum var. ischaemum (yellow bluestem).
Alyssum maritimum is now Lobularia maritima (sweet alyssum).
Cytisus spinosus is now Calicotome spinosa (spiny broom).
Setaria is the genus of bristlegrass.
The achenes (small indehiscent fruit) of Platanus orientalis (the oriental plane tree) form an aggregate ball, with each achene having a tuft of bristles.
Moggridge maintained that several plants in the genus Ophrys that CD had treated as species (O. scolopax, O. arachnites, O. aranifera, and O. apifera) were only varieties of one species, which he called O. insectifera (see Correspondence vols. 12–14). In ‘Fertilization of orchids’, p. 145, CD noted Moggridge’s theory, adding that in England the forms did not appear to be varieties of a single species; however, see also Orchids 2d ed., pp. 58–9, where CD raised the possibility that the Italian forms, unlike the English ones, had not yet been fully differentiated into species. The name O. insectifera now refers to the fly orchid, known to CD as O. muscifera.
Moggridge began working on varieties of Viola odorata in 1867 (see Correspondence vol. 15, letter from J. T. Moggridge, 6 March [1867] and n. 4). Alexis Jordan was a French botanist known for giving specific status to forms that were generally considered to be only varieties; he described seventeen species of Viola in Jordan 1851, pp. 225–40.
Narcissus tazetta is the cream narcissus. Jordan divided Clypeola jonthlaspi into C. psilocarpa, C. petraea, and C. semiglabra (see Jordan and Fourreau 1866–1903).
Moggridge’s Contributions to the flora of Mentone was separately published in four parts between 1865 and 1871 and then as a single volume in 1871 (Moggridge 1871).

Summary

At Wallace’s suggestion he offers CD his observations on the seed-gathering habits of ants. Suggests their role in seed dispersal.

At work on the last part of his book [Contributions to the flora of Mentone (1867–71)].

Has found that Ophrys insectifera can reproduce asexually.

Letter details

Letter no.
DCP-LETT-7788
From
John Traherne Moggridge
To
Charles Robert Darwin
Sent from
Richmond
Source of text
DAR 171: 215
Physical description
10pp

Please cite as

Darwin Correspondence Project, “Letter no. 7788,” accessed on 23 April 2019, http://www.darwinproject.ac.uk/DCP-LETT-7788

Also published in The Correspondence of Charles Darwin, vol. 19

letter