372 SHELLS, (Cuar. XI. 
BERTOLACCI mentions a curious local peculiarity! 
observed by the fishermen in the natural history of the 
chank. “All shells,” he says, “ found to the northward 
of a line drawn from a point about midway from Ma- 
naar to the opposite coast (of India) are of the kind 
called patty, and are distinguished by a short flat head ; 
and-all those found to the southward of that line are 
of the kind called payel, and are known from having a 
longer and more pointed head than the former. Nor is 
there ever an instance of deviation from this singular 
law of nature. The Wallampory, or ‘ right-hand 
chanks,’ are found of both kinds.” 
This tendency of particular localities to re-produce 
certain specialities of form and colour is not confined 
to the sea or to the instance of the chank shell. In 
the gardens which line the suburbs of Galle in the 
direction of Matura the stems of the coco-nut and jak 
trees are profusely covered with the shells of the beau- 
tiful striped Helix hemastoma. Stopping frequently 
to collect them, I was led to observe that each separate 
garden seemed to possess a variety almost peculiar to 
itself; in one the mouth of every individual shell was 
red; in another, separated from the first only by a wall, 
black ; and in others (but less frequently) pure white ; 
whilst the varieties of external colouring were equally 
local. In one enclosure they were nearly all red, and 
in an adjoining one brown.? 
1 See also the Asiatic Journal borne about half of some of the 
for 1827, p. 469. 
2 Darwin, in his Naturalist’s 
Voyage, mentions a_ parallel in- 
stance of the localised propagation 
of colours amongst the cattle which 
range the pasturage of East Falk- 
land Island: “Round Mount Os- 
herds were mouse-coloured, a tint 
not common anywhere else, —near 
Mount Pleasant dark-brown pre- 
vailed ; whereas south of Choiseul 
Sound white beasts with black 
heads and feet were common.”’— 
Ch. ix. p. 192. 
