Ɛpsilon

From Sarah Marshall   7 November 1881

92 Warwick Gardens | Kensington W.

Nov 7. 1881.

Honored Sir,

You will pardon my troubling you with a scientific question. I should not dream of intruding on an instant of your valuable time had I not first tried to study out the matter & to question others.—

Can you refer me to any book or authority or yourself throw light on the question of the reason the Bulimus decollatus being always broken at the apex as an adult mollusk.1

I have found hundreds of them in hollows under the marble fragments of the Parthenon, on Mounts Pentelicus and Lykabetus, in many places in Asia Minor the Troad &c.2

The adult mollusk side by side with the delicate fragile unbroken young Bulimus d, and other mollusks much more fragile of many kinds.

The abrasion of the apex in Unio, Trochus3 &c &c is apparently involuntary while in B.d. the same amount being broken in each specimen looks as voluntary as the self mutilation in the case of ants when they bite off their wings.4

Yours obediently | S. Marshall.

1
Bulimus decollatus is a synonym of Rumina decollata (the decollate snail), a land snail with a cone-shaped shell, the end of which is ground or chipped by rubbing against hard surfaces when the snail reaches maturity.
2
Pentelicus is a mountain in Attica, Greece; Lycabettus is a hill in Athens. The Troad or Troada is the historical name of the Biga peninsula, which borders the Aegean Sea in modern Turkey.
3
Unio is a genus of freshwater mussels. Trochus is a genus of sea snails; the shells have a conical spire.
4
In most ant species only queens and males possess wings. The ants fly from their nests, swarm, and mate in order to create new colonies. After mating, males die and the queens pull off their own wings, using the remaining wing muscles as a source of nutrients for the new brood.

Please cite as “DCP-LETT-13470,” in Ɛpsilon: The Charles Darwin Collection accessed on 5 June 2025, https://epsilon.ac.uk/view/dcp-data/letters/DCP-LETT-13470