372 



SHELLS. 



[Chap. XI. 



Bejrtolacci mentions a curious local peculiarity 1 

 observed by the fishermen in the natural history of the 

 chank. " All shells/ 5 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 pajel, 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 6 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 Gralle 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 hcemastoma. 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. 2 



1 See also the Asiatic Journal borne about half of some of the 

 for 1827, p. 469. herds were mouse-coloured, a tint 



2 Darwin, in his Naturalist's not common anywhere else, — near 

 Voyage, mentions a parallel in- Mount Pleasant dark-brown pre- 

 stance of the localised propagation vailed ; whereas south of Choiseul 

 of colours amongst the cattle which Sound white beasts with black 

 range the pasturage of East Palk- heads and feet were common." — 

 land Island: "Kound Mount Os- Ch. ix. p. 192. 



