518 



SCIENCE. 



[Vol. V1L, No. 175 



a great range of variation in color, a few being 

 bright crimson-red, while the majority are of a 

 dirty greenish-yellow tint. Similar variations in 

 color are apparent in the young after hatching, 

 and are apparently due, as in the case of the eggs, 

 to the presence of an unusual number of red- 

 pigment cells. 



Immediately after hatching, the young swim 

 about in the sea-water, and will at once begin to 

 feed, even killing and eating each other if food is 

 not soon offered them. Minced crab or lobster 

 meat is greatly relished. The recently hatched 

 lobsters are also attracted by the light, and will 

 always collect at the side of the aquarium or tank 

 nearest the source of light. At night, or if the 

 light is shut off, the young lobsters go to the bot- 

 tom of the tanks ; and it seems that they may 

 then be most actively engaged in feeding if food 

 is placed within their reach. 



When first hatched, the young lobster measures 

 one-third of an inch long, and is provided with 

 cephalothracic appendages only. The tail, unlike 

 that of the just hatched crayfish, is without 

 swimmerets. The five thoracic appendages, unlike 

 those of the adult or those of the young crayfish, 

 are biramose, the outer branches or rami being 

 flattened, and fringed with plumose setae. These 

 outer branches of the limbs are rapidly vibrated 

 to and fro, and constitute the principal locomotive 

 appendages of the young lobster during the 

 pelagic stage of its existence, acting like paddles 

 or oars and independently of the inner rami, 

 which are used mainly as prehensile organs. The 

 inner rami of the appendages afterwards become 

 the permanent thoracic limbs, while the outer 

 ones abort. 



When from four to six days old, they moult for 

 the first time ; and it is noticed that in doing so 

 they suddenly increase in length and bulk, since 

 they now measure nearly half an inch in length. 

 They also, at this time, acquire four pairs of ab- 

 dominal legs or swimmerets; but the telson is 

 still formed of a broad, single, triangular piece, 

 emarginate posteriorly, and not rounded and ser- 

 rated behind as in the young crayfish. The 

 pincers of the first pair of thoracic limbs become 

 distinctly developed at the first moult. 



It is obvious, from what has preceded, that the 

 lobster passes through aschizopod stage, as pointed 

 out by S. I. Smith. This stage has been omitted 

 in the ontogeny of the crayfish. The young also 

 evidently abandon the mother lobster at once, the 

 blades of their pincers being without hooked tips 

 for clinging to the mother, as in the recently 

 hatched crayfish. 



In the course of about eight days more, the 

 young lobsters probably moult again, — a process 



which is repeated for the third time in the course 

 of perhaps ten days more, when they will measure 

 about five-eighths of an inch long, and when they 

 have acquired an additional pair of appendages, 

 so that they then have all that are possessed by 

 the adult. 



The young lobster probably moults twice more 

 before it is sixty days old, by which time its 

 antennae become fully developed and flagelliform, 

 while its telson loses its larval form, and the 

 animal has thus completed its metamorphosis. It 

 now measures about an inch in length, and is 

 occasionally taken at the surface in a tow-net, 

 though it is probable that it now usually remains 

 at the bottom, concealing itself among the sea- 

 weeds and stones, lying in wait for its prey. 



Recent experiments conducted by Captain 

 Chester, at Wood's Holl, have demonstrated that 

 it is possible to keep the adult lobsters alive for 

 an indefinite period in a moist, cold atmosphere. 

 These conditions may be most readily satisfied by 

 packing the lobsters between layers of wet seaweed 

 in a metal box with a perforated cover ; this metal 

 box being then placed in a larger wooden box, 

 and surrounded with cracked ice, which will cool 

 the contents of the inner box down to 45° F. At 

 this temperature, in this device, lobsters have 

 been kept alive and in good condition for fifteen 

 days, and in a moist atmosphere only ; their gills 

 not having been immersed in water during the 

 whole period. Even the eggs hanging to the 

 swimmerets of the females so treated are not 

 injured in the slightest degree, and will continue 

 to develop normally if put into the hatching-jars. 

 The adults also, if taken out of the seaweed in 

 the metal box, and put into sea-water, have the 

 moist air in the gill-chambers at once replaced by 

 the water, and begin to move about as if nothing 

 had happened to them. 



This important discovery renders it possible to 

 transport living adult lobsters across the continent, 

 and to stock the waters of the Pacific coast with 

 this important crustacean. It is also possible to 

 pack the eggs in seaweed in a similar manner, 

 and transport them for long distances, after 

 which they may be hatched and reared up to an 

 inch in length by artificial means. This will 

 render it possible to collect lobster-eggs to the 

 number of many millions at several points over 

 the fishing-grounds, and bring them to a great 

 central hatching and rearing establishment, such 

 as that at Wood's Holl, where at least a hundred 

 million eggs may be cared for at one time. The 

 work of propagating the lobster, the cod, and 

 other fishes, will then keep the station at Wood's 

 Holl in practical operation, in an economic direc- 

 tion, for the entire year. The recent successes at 



