[page 489]

[Annotation by Darwin:] Could they when dying be transported by gales of wind?

MISCELLANEOUS.

ON THE TENACITY OF LIFE IN SNAILS.

DEAR SIR,

Last year I was told by Mr. Pickering that he had procured some foreign Cyclostomæ of Argent, which he kept some weeks, and then resuscitated by placing them in water; also that he had received a whole basketful of Madeira snails, of various species, from Mr. Wollaston, which after several months' fasting and captivity were revived in the same manner. Naturalists, who make foreign tours, seldom have the time or means of killing and cleaning large numbers of land-shells; it is therefore satisfactory to know that, with a little care in packing, a collection may be brought home alive and attended to at leisure. The following particulars, communicated to me by Mr. Wollaston, will show to what extent this may be done:—

"25 Thurloe Square, Brompton, Oct. 19, 1850.

"During my residence in the island of Porto Santo, from April 27 to May 4, 1848, I collected a large quantity of Helices peculiar to the spot, and having placed a small set of each, as types, in separate pill-boxes (for examination by Mr. Lowe on my return to Madeira), the rest were killed. These types were named the following week by Mr. Lowe; and as I had to leave immediately for England, I had no time to kill the specimens. On my return home the boxes were placed in empty drawers of my insect-cabinet, since which, up to the present time (Oct. 19, 1850), they had never been opened, or if opened, the specimens had certainly never been taken out. I concluded of course that they were dead long ago, thinking it more than probable that they never survived the voyage to England, and therefore, à fortiori, that two years and a half in dry pill-boxes was quite sufficient to remove all traces of existence. However, by immersion in cold water, I find that many of them are still alive; and though a large proportion have perished in this long interval, yet I have fourteen specimens now before me crawling about with the greatest activity. Thirteen of these are of the same species, viz. Helix (Carocolla) papilio, Lowe; and the other Helix tectiformis, Lowe, both collected May 1st, 1848, on the Ilheo de Baxo, a small limestone island off the south-western extremity of Porto Santo. And that there can be no possible mistake in this statement is made perfectly clear by the fact that Helix papilio is found in no other locality, and that May 1st, 1848, was the only occasion on which I have ever visited that remarkable rock. I regret that many of the types placed in the pillboxes at the time of collecting were (purposely) dead specimens, as being sufficient for the mere discrimination of the species.

"I may also mention that I possess a whole bagful of the beautiful little Helix turricula, Lowe, collected on the Ilheo de Cima (another and smaller rock, off Porto Santo,) on the 24th of April 1849,—all of which, I find by immersion, are alive, though the dry and dusty bag in which they have been inclosed has never been

[page] 490 Miscellaneous.

opened since they were placed there, exactly a year and a half ago. The same may be said of Helix duplicata and paupercula of Lowe (collected at the same time as the last); I have both in large quantities, perfectly active, though only now for the first time taken out of the boxes in which they were originally placed.

"I have also a few specimens of a minute Madeira species, Helix lentiginosa, Lowe, which I have ascertained to be alive, although they are so small that it is difficult to conceive how sufficient moisture to support life can have been retained through this long period." These observations, made by an accurate and trustworthy naturalist, may well take the place of those extravagant stories—borrowed from newspapers —which we too often find detailed in "popular Conchologies."

Yours truly,

S. P. Woodward.

W. Francis, Esq.