762 BULLETIN OF THE BUREAU OF FISHERIES. 



appropriate shape floating in the water between the pontoons of the houseboat. 

 In this case hving food was suppHed at first in the form of small barnacles which 

 had set on boards, and later, as the starfishes grew larger, clams, oysters, and 

 mussels were given them to eat. The conditions in these cars were completely 

 adequate for the healthy life of these slow-moving animals, and were abnormal 

 only in that the young starfishes were protected from their enemies (excepting 

 always their cannibal brethren) and were better fed than they often are under 

 natural conditions. In many cases where they were especially well fed they 

 far outstripped in rapidity of growth individuals found along the shore. They 

 throve splendidly and were perfectly healthy. 



This way of raising starfishes may hardly be dignified by the term " method," 

 and yet the better condition of these specimens as compared with those usually 

 seen in an aquarium — even in an aquarium where many fishes live for a long 

 time — is a striking fact. It suggests also that there is often something the matter 

 with aquarium water which, whatever the cause, makes it unsuitable for the 

 rearing of very sensitive animals. 



At the floating laboratory, animals with the burrowing habit can also be 

 kept confined and protected and under constant observation by simply putting 

 them into a box of sand suspended in the water. Specimens of the soft-shell 

 clam {Mya arenaria) may in this way be very successfully and rapidly reared, 

 and they give every indication of being in a perfectly normal environment. 

 Indeed, in our experiments, when they were kept just under the surface of the 

 water and in the tidal current, they grew more rapidly than in the most favorable 

 shore locaUty I have ever seen. In one experiment with clams ranging from 5 

 to 17 miUimeters the increase in bulk during five weeks and two days was i,86i 

 per cent. 



In the case of sessile animals like oysters, Crepidula, Anomia, Molgula, 

 Botryllus, sea anemones, tubiculous worms, etc., and of those which spin a 

 byssus, like the mussel, young clams, and pectens, it is only necessary to provide 

 the proper surface for them to set on and protection from predatory animals. 

 In case of the hatching of such eggs as those of the flatfish, Menidia, Fundulus, 

 and the lobster, with which we have had experience in the course of our opera- 

 tions, it would seem that the term "hatching" could hardly be used in a transi- 

 tive sense, for, if the eggs are provided simply with water of proper constitution, 

 temperature, and conditions for respiration, the eggs inevitably hatch them- 

 selves. These nonpelagic eggs, in fact, belong to the same category as the 

 sessile or slow moving animals and may be treated accordingly. The method 

 of stripping and swirling lobster eggs has been given up with us and instead the 

 ripe-berried hen-lobsters are allowed to crawl about in the rearing cars with the 

 result that the eggs hatch most satisfactorily. Similarly the eggs of the flatfish 

 (Pseudopleuronecfes) were hatched with almost no loss by placing them on a 



