348 BULLETIN OP THE BUREAU OF FISHERIES. 



It was shown that young lobsters did not uniformly make their descent to nether 

 regions during the fourth stage or even at its end, and that the swimming period often 

 lasted to the fifth stage, probably until its close, and possibly into the sixth stage. 

 I have records of young lobsters captured under natural conditions at the surface of 

 the sea (see 149, table, p. 187), varying in length from 15 to 18 millimeters. The 

 largest, taken 7 miles southwest of No Man's Land, near Marthas Vineyard, 18 milli- 

 meters long, was probably in the fifth stage, though possibly in the sixth, as seemed to 

 me very likely at the time. Hadley's measurements for Wickford (R. I.) lobsters, 

 which average much higher than those obtained by me at Woods Hole, Mass., are for 

 the stages in question as follows: Fourth stage, average length, 13.5 millimeters 

 (extreme, 15.5 mm.); fifth stage, average length, 16 millimeters (extreme, 18 mm., 

 two records only); sixth stage, average length, 18.8 millimeters (extreme, 24 mm., one 

 record). (See also later measurements quoted above.) The average length for lobsters 

 raised in aquaria at Woods Hole in the same stages are as follows: 12.6 millimeters 

 (extreme, 14 mm.); 14.2 millimeters (extreme, 15 mm.); 16. r millimeters (extreme, 

 17 mm.). Inasmuch as size is a very unsafe criterion of either stage or age, it can 

 not be said that at present there is any satisfactory evidence that the American lobster 

 remains at the surface beyond the fifth stage. It is interesting, however, to notice a 

 record by Meek {200) of the capture by surface net of a young specimen of the European 

 lobster, which measured 20.5 millimeters (yf inch), at Alnmouth Bay, Northumberland, 

 England, in the afternoon of September 7. Its age was estimated at 2 months. Now 

 according to Ehrenbaum (87), whose work was conducted at Helgoland, such a lobster 

 should be in either the sixth or seventh stage and upward of 61 or 87 days old, 

 respectively (sixth stage, length, 18-20 mm.; seventh stage, length 21-22 mm.). We 

 should therefore hesitate to affirm that in the American form the swimming life at the 

 surface is never extended to the sixth stage. 



The experiments of Hadley and others on the reactions of the larvse show that the 

 Ught-shunning, bottom-seeking, and hiding tendencies begin to assert themselves in 

 animals artificially reared toward the close of the fourth or else in the fifth stage. 



The bearing of this question upon the artificial propagation of the lobster is very 

 evident, for, if a considerable number of fourth-stage lobsters remain suspended at the 

 surface, the careful rearing to this stage and subsequent liberation in the sea is only 

 feeding the fishes. A small force of predaceous tautog, or cunners, would play havoc 

 with myriads in a short time. As we remarked in 1895, "the problem of the artificial 

 propagation of the lobster will be solved when means are devised by which larvae, after 

 hatching, can be reared in inclosures until the fifth or sixth stage, when they can take 

 care of themselves." This time limit should have been modified to read "until they go 

 to the bottom." The lack of precision which the lobster displays in his desire to 

 discover the bottom is very disappointing, but it seems evident that liberation of the 

 carefully reared young at the very beginning of the fourth stage is only to court disaster, 

 with the attendant waste of time, money, and labor. 



