120 REPORT OF COMMISSIONER OF FISH AND FISHERIES, 



depth were so suspended in the pool of the floating laboratory that the current could 

 not change their general shape or cause them to collapse. In each bag was placed a 

 dasher, the blades of which in rotation would constantly lift the water through the 

 mesh at the bottom of the bag and urge it with obviously less velocity through the 

 pores of the vertical walls. The dashers were kept in motion by means of a small 

 gasoline engine. We found that when the mechanism was in actual o^jeration, the 

 current, in rising through the bottom of the bag, brought with it large numbers of 

 pelagic animals, while the reduced current of the water passing through the greater 

 expanse of the vertical walls was not sufficient to carry this living material out of the 

 bags; thus the apparatus sufficed not only for keeping the fry and artificial food from 

 the bottom, but also provided the fry with living natural food. To Mr. G. H. Sher- 

 wood is due the credit of devising and installing this aerating and feed apparatus. 



In practice it was found that the eggs strippetl from the abdomen of the female 

 would hatch in these scrim inclosures under much more favoral)le conditions than 

 in the McDonald jars. Indeed, I am inclined to believe that a far higher percentage 

 of eggs would hatch in these bags than in the McDonald jars, and I am sure that the 

 young are in a much more healthy condition than when hatched by the older 

 method. Even a superficial examination of the young that have spent some hours 

 in the trituration of the McDonald jars will show that a large proportion of them 

 have the appendages broken, bent, or indented. 



The number of fry that were available for the purpose of experimentation during 

 the first season was considerably less than in 1900, and the period of experimental 

 work was also materially reduced. Nevertheless, Dr. Mead, who had the work imme- 

 diately in charge, reports that by actual count in no case was the number of lobsters 

 that reached the fourth stage less than 16 per cent of the number of fry originally 

 placed in the inclosure. In a few cases it was above 40 per cent, and in at least one 

 case it was as high as 54 per cent. In previous years no experiments had yielded 

 more than a fraction of 1 per cent. The total number of lobsters raised to the fourth 

 stage during the season of 1901 (in the 12 cylinders) was a little more than 9,000. « 



OYSTER-FATTENING EXPERIMENTS AT LYNNHAVEN. 



For several jears past the Commission has been conducting experi- 

 ments in Ljmnhaven, Va., under the direction of Messrs. H. F. Moore 

 and W. W. Blackford, for the purpose of developing a method by 

 which oysters may be fattened artificiallj'^ with the same degree of 

 certainty attained by stock-raisers in fattening cattle. 



The practice of allowing oysters to fatten on the beds where they 

 are grown is haphazard in its methods and uncertain in its residts, and 

 coves and other places where the natural food supply is sufficiently 

 great at all times and under all conditions are too rare to be available 

 to most oyster-growers. Ordinarily there is no difficulty in raising 

 03'sters to a marketable size within a reasonable time, but there is 

 often considerable difficult}^ in producing them in a marketable condi- 

 tion. Frequently a grower will be unable to ship during a large part 

 of the most profitable season because for some reason, which he can 

 not control, the oysters will not get fat. This difficultv often happens 

 unexpectedly, even within the most favorable localities, and causes 

 the grower to hesitate to enter into contracts which he could protitably 



fiThe results attending the experiments in lobster culture made by the U. S. Commission of Fish 

 and Fisheries, Science, December 27, 1901. 



