162 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 
The Sand Dab (Pleuronectes maculatus). 
On May 12, 1890, Mr. Edwards secured about 100,000 eggs of this 
species, which, in a temperature of 51° to 54° F., hatched on the fifth 
day, with a loss of only 10 per cent. The tidal cod jar was used for 
this purpose. The eggs are buoyant, and about 24 are contained in a 
linear inch. 
The Four-Spotted Flounder (Paralichthys oblongus). 
Of this species, 50,000 eggs were obtained on May 15, 1890. They 
are of the same size as the eggs of the sand dab, are also buoyant, and 
hatched in the same length of time, but with a loss of 50 per cent. 
The tidal cod jar was employed. 
The Lobster (Homarus americanus). 
In previous reports accounts have been given of thie successful at- 
tempts made to hatch lobster eggs which had previously been removed 
from the swimmerets of the parent, but at the same time attention was 
called to the difficulty of rearing the embryos in captivity, owing to 
their propensity to devour one another, notwithstanding great care 
Was exercised in supplying them with proper food. On this account the 
embryos have generally been planted when only a few days old, but it 
is considered that much better results could be accomplished by confin- 
ing them in tanks until they had reached an age of 4 or 5 weeks, when 
they are better able to protect themselves against their enemies. 
During 1890 and 1891 the hatching work was continued at Woods Holl 
on a moderate scale, and at the same time careful experiments were 
made to discover some way of keeping the larvee in the aquaria without 
the great mortality which has hitherto occurred. Mr. V. N. Edwards 
also made some interesting observations regarding the eggs and the 
size at which the adult first becomes mature, and important studies re- 
specting the breeding habits and life history of the species were under- 
taken by Prof. F. HW. Herrick, of Adelbert College, and Prof. H. C. 
Bumpus, of Brown University. Prof. Herrick first turned his attention 
to this matter during the summer of 1889, and in the following year 
arrangements were made with him to prepare a comprehensive mono- 
graph covering the entire subject, which will probably require several 
years forits completion. Prof. Bumpus was at the station in the spring 
of 1890. Preliminary reports have been published by Prof. Herrick in 
the Johns Hopkins University Circular No, 80, 1890, and No, 87, 1891, 
the latter containing the two following papers by him, namely: “ Notes 
on the habits and larval stages of the American lobster,” and ‘The 
reproductive organs and early stages of development of the American 
lobster.” 
From the inquiries made up to this date some very valuable dedue- 
tions have been reached. The fact that the eggs laid during the sum- 
mer are carried by the parent until the following spring or summer 
before hatching, a conclusion reached by the writer from his experi- 
ments in 1885, has been proyed conclusively, During 1889, eges were 
