234 BULLETIN OF THE BUREAU OF FISHERIES, 
adopted the annoyance from this source is very slight when the cars are shaded. 
The insides of all of the boxes were painted, four of them white and the rest 
green. We could not see that either color had an advantage, judging from the 
‘output of fry. Whether the comparative immunity from diatoms of fry in 
boxes as compared with those in canvas bags was due to the painted surfaces 
of the wooden sides or to some other factor it is difficult tosay. Animal growths, 
barnacles, molgulas, oysters, mussels, etc., were abundant even on the painted 
surfaces, and were scraped off each time the cars were raised. Canvas screens on 
frames (fig. 7, pl. x), set up like the sides of a roof so as to afford shade and 
to shed rain water, which occasionally comes down in such quantities as decid- 
edly to freshen the upper strata of water, are strongly to be recommended. 
RESULTS. 
CRITERIA OF EFFICIENCY. 
As was stated at the outset, this series of experiments and operations was 
undertaken in the conviction that the paramount problem of lobster culture was 
to raise the larve to the fourth or lobsterling stage. It has been constantly 
borne in mind that a method of doing this to be practical must be able to pro- 
duce large quantities and without too great expense either for the cost of the 
plant or for operation. Further criteria of efficiency are, first, the proportion 
of fourth-stage lobsters to first stage, and, second, the number of ‘“‘fours” to 
egg lobsters, provided, of course, that the egg lobsters on hand do not over- 
crowd the capacity of the particular plant. In placing a value upon propor- 
tions of ‘‘fourth stagers’’ to newly hatched fry, the number of fry dealt with in a 
single experiment has been considered; e. g., a proportion of 50 per cent carried 
through in an experiment with 500 or 1,000 fry can not fairly be compared 
with the same proportion in an experiment in which 5,000 or 20,000 fry are 
used. We have allowed ourselves also to mark our progress and the value of 
the method by comparison, first, with our former results, and, second, with the 
experiments undertaken elsewhere having the same end in view. 
YEARLY PROGRESS AND OUTPUT. 
Since this year happens to be the decennial of this particular series of 
experiments and operations, the presentation of a short summary of yearly 
results in regard to total output is appropriate. 
In 1898 Doctor Bumpus, now the honorable president of this congress, and 
at that time director of the United States Fish Commission laboratory at Woods 
Hole and member of the Rhode Island Commission of Inland Fisheries, had the 
faith and courage to undertake a new series of experiments in rearing the larval 
lobsters. Judged by the ingenuity put into them, and the experience and 
encouragement got out of them, these experiments during the first year were 
