TRANSPLANTATION OF BIVALVES. 75 



Cyclas cornea abounded, observed a number of the 

 shells clinging ''with the greatest tenacity'^ to the 

 toads, some of which had no less than three shells on 

 each of the hind feet, while instances in which the toes 

 were entirely free were very rare. None of the shells 

 were attached to the fore feet/ Mr. Standen, according 

 to his published note of 1885, has also seen the toes of 

 toads firmly grasped by these shells,^ and in April, 

 1892,, when a number of toads were spawning in the 

 " leg-of-mutton " pond on Hampstead Heath, I fished 

 out an individual with a fine shell of the same kind on 

 a toe of one of the hind legs (Fig. 5). 



These cases^ it will be seen, furnish no actual 

 evidence of dispersal, for the amphibians, I believe, were 

 all caught in water or in its immediate vicinity. It is 

 obvious, of course, that such animals can never carry 

 shells to great distances, and if we are to form an 

 opinion as to the extent to which they have affected 

 /^^^/ distribution, we ought to know something of their 

 habits, whether they often journey from one piece of 

 water to another, etc., but as to this I have little or 

 no definite information. Some edible frogs {Rana 

 esculenta), turned loose by Mr. Henry Doubleday near 

 a pond by his residence, it is said, ^' soon migrated to 

 another pond ; '' ^ Mr. Darwin gives a statement, on the 

 authority of Mr. Norgate, that newts migrate at night 

 from pond to pond, and can cross over obstacles which 



1 J. Peers, " Zoologist," xxiii. (1865), 9697-8. 

 ' R. Standen, "Science Gossip," xxi. (1885), 281. 

 3 E. Newman, "Zoologist," vi. (1848), 2268. 



