THE AMERICAN LOBSTER. 
61 
only about 50 young ones were observed. The remainder of the eggs are still in jars in good condi- 
tion. A few of the embryos were transferred to an aquarium with running water, and others to a 
small vessel in which there was no change of water. The former lived about 24 hours, the latter about 
36 hours. The temperature of the water in the hatching jar November 5 was 54.3° F. ; on the 6th, 
55°; and on the 7th and 8th, 56°. * * * The conditions under which the eggs were kept were 
perfectly normal, the water being of about the same temperature as that of the harbor outside. 
1 have learned of another very interesting case of the artificial hatching of the 
eggs of tlie lobster out of the regular season. This happened during the latter part 
of January and the first ten days of February, 1889, at the hatchery of the United 
States Fish Commission at Ten Found Island, Gloucester, Massachusetts. Mr. E. M. 
Robinson, to whom I am indebted for these facts, was at that time superintendent of 
the station. He says that the eggs were clipped from the lobster at about Christmas 
time, and suspended in aquaria through which sea water was constantly running. 
The temperature of the water was very low, at least as low as 36° F., and as many as 
10,000 lobsters were hatched under these conditions. 
Mr. Nielsen, who visited the station at that time, corroborates this account, so 
far as the actual hatching of young lobsters is concerned. He writes that he examined 
with the microscope a young lobster which had been hatched on the day of his visit. 
The larva had perished in breaking out of the egg and in passing its first molt, but 
was perfectly developed in every way. 
These facts clearly show that the hatching period varies in the same way that the 
time of egg-laying varies. The one must be correlated with the other. 
William II. Wheildon gives some interesting facts about the lobster in a short 
paper published in 1875 (202), already referred to. He says: 
In February of the present year we exhibited spawn in several stages of development from newly 
laid eggs to the swimming larva 1 . 
The fact that the lobsters are with eggs in every month, of the year, and that young 
sometimes make their appearance in wiuter and fall, does not prove, however, as this 
writer, like so many others, inferred, that the animal has no particular breeding season, 
but from these facts alone it would never have been possible to have arrived at a clear 
understanding of the reproductive habits. To the circumstance that egg-lobsters are 
taken at all seasons and often with eggs in very different stages of development is 
due, more than to anything else, the confusion which had settled down upon this most 
important phase in the life-history of this annual. 
In the case of the lobsters hatched at Woods Hole in early November, 1885, the eggs 
were probably laid in the late winter or spring of the same year. I have the record 
of a lobster which had in all probability spawned as early as June 20 (table 3, No. 2). 
Supposing these ova to have been extruded by the first week in June, they would 
have had five months, including the warmest period of the year, for their development. 
For five months, from the first of December to the first of May, the eggs are subjected 
under natural conditions to a relatively low temperature, and their development is 
greatly retarded. Consequently a batch of eggs which is extruded at the first or 
middle of August and hatched in May or June following is not, in all probability, 
subjected to a greater number of heat units than eggs which are laid in June and 
hatched in November. The embryos grow very slowly during the winter months, but the 
advancement may be sufficient, when development has already proceeded far enough 
in the fall, to bring the embryo to the point of hatching under favorable circumstances 
in winter. 
