OBSERVATIONS ON THE LIFE-HISTORY OF THE COMMON CLAM. 
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men, a very profitable business. In localities where it has been impossible to obtain 
a set of “ spat,” where the beaches between tide marks may not be used, where an 
annual rental of $10 an acre must be paid, where the deadly star-fish abounds, and 
where oysters are purchased abroad and shipped great distances simply to be spread 
upon the bottom and allowed to grow to a marketable size, the business pays and is 
thriving. One or two attempts have been made to develop methods of clam-culture 
in this country, but for various reasons — principally because of a lack of protection 
by law from the depredations of clam diggers — they have been discontinued. 
From the account of the life-history of the long-necked clam here given, it would 
appear that it may be possible to develop culture methods which should be productive 
of much greater results than those obtained by oyster culture. Two or three points 
elucidated, as well as some facts not yet mentioned, may well be noticed as bearing on 
the solution of this economic problem. 
The habit of attachment. — Probably in many localities it would be possible, as it 
is in the Kickemuit Eiver, to obtaiu great numbers of young clams in the early summer 
by simply gathering floating seaweed to which they are attached and transporting them 
to localities where conditions should be most favorable for further development. 
Though no facts bearing on this point are at hand, it may be possible to bring 
about an artificial fertilization of the ova of the clam in such a way that the swimming 
larvae might be induced to attach to some suitable object which should be convenient 
to handle when it is suspended in the water containing the embryos. This has been 
accomplished with some degree of success in the case of the oyster, where artificial 
fertilization may be brought about with very great ease; but with some lamellibranchs 
it seems absolutely impossible to induce this union of the sexual cells, and this may 
be the case with the clam. Even if it were so, sexually mature individuals might be 
placed in inclosed localities, where large numbers of the young could be collected. 
Tenacity of life. — While the adult Mya dies quickly in aquaria, the small clams are 
very tenacious of life. Early in July, 1898, a bucket full of Enteromorplia , covered with 
clams, was taken from the water at the Kickemuit Narrows at 11 a. m. of a hot day, 
and was carried to Woods Hole, arriving at 4 p. m., the water in the bucket having 
become very warm. The clams were transferred directly to the much colder sea water 
in the hatching-house of the IT. S. Fish Commission station. None of them seemed to 
be in the least injured by their rough treatment, and they lived in very slowly running 
water for over a month, when they were removed. In this case, no care having 
been taken to make the conditions favorable, they did not seem to thrive, and certain 
individuals measured from time to time showed little or, in some cases, no growth. 
Others, after remaining a month in the hatching-house, were placed in small glass 
dishes, which were allowed to stand until the water had nearly evaporated and a zooglea 
mass had formed on top of it, and they remained alive under these conditions for many 
days. These facts seemed to indicate that the small clams are very hardy and that, if 
desirable in culture work, they could easily be transported without injury. 
Effect of n-aters of differing degrees of salinity. — In the transfer of clams just 
mentioned, it may be noticed that the salinity of water in the two localities is some- 
what different. In the Kickemuit the average salinity is about 1.019; at Woods Hole, 
about 1 .024. As is the case with oysters, clams will live in water which is brackish. At 
the salt pond near Wakefield, Rhode Island, for instance, the salinity is from 1.0049 
to 1.0058 on the surface, and quite a number of clams are found along its shores. 
The density at the bottom may be much greater than at the surface, however. 
