I was greatly interested to receive specimens of ants, and of the seeds which they were carrying and storing beneath the stones of a paved road at Cadenabbia, for this is the northernmost point[110] at which the habit of harvesting has as yet been noted. This discovery suggests the possibility of the occurrence of the habit in the warmer and more sheltered of the Swiss valleys. When at Montpellier in May last I frequently observed long trains of ants bringing seeds and small dry fruits to their nests, but these harvesters also turned out on close inspection to be _Atta structor_ and _A. barbara_, with its red-headed variety. These, it will be remembered, are the only species of European ants which have as yet been proved to be harvesters and seed-storers in the fullest sense of the term, that is to say, which not only gather and carry seeds, but also store them in large quantities below the surface of the ground.[111] [Footnote 110: I have related in a note at the foot of p. 4 in _Ants and Spiders_ how _Formica nigra_ in England, though paying no attention to seeds generally, will sometimes collect the fresh seeds of the sweet violet (_Viola odorata_). When I published this account I was quite unaware that the fact that certain English ants collect sweet violet seeds had been observed by Mr. R. Wakefield forty years before. This was communicated by Mr. Wakefield in a letter to Mr. John Curtis, the substance of which was read before the Linnean Society in 1854, and published in their Proceedings (see Proceedings of the Linnean Society, ii. 293), where we read: "He (Mr. Wakefield) states that he has seen the black species (_Formica nigra_, L.) for days and nights together industriously occupied in dragging to its cells the seeds of the common violet (_Viola odorata_, L.) "He first noticed this fact on the 3rd of July, 1832; and he regards it as a curious subject of inquiry for what purpose, if not for their own future provision, they could accumulate these stores?" Mr. Wakefield appears to accept this as evidence that these ants possess the habit of storing seeds; but this is not so, as will be seen by reference to my note alluded to above, and I am inclined to believe that they collect these particular seeds either under the mistaken belief that they are larvæ, to which when fresh they bear some resemblance, or for the sake of some juices which they may obtain from the fleshy appendage attached to the seed.] [Footnote 111: Six other species belonging to the genus _Atta_ are found in Europe, but they are all unknown to me. It seems likely that, if other harvesting ants do exist in Europe they may belong to one of these six species; for we have seen (_Ants and Spiders_, p. 59) that all the ants which are known to possess this habit are either members of the genus _Atta_ or belong to genera closely related to it.]