LOBSTER INYESTWATIONS 61 



SESSIONAL PAPER No. 38a 



by keeping track of those which die from year to year, and ascertaining, if possible, 

 the cause of death. For example, of 167 lobsters left in the pond and pound last 

 season (1914) only 134 could be found this season, thus showing a loss of 33. Of the 

 312 placed in the pond and pound this season (1915) all have been accounted for, the 

 loss by death being a total of thirty-eight. But, just as thirty-three in the one case 

 does not represent the true loss by death (because some of last year's lobsters may yet 

 be recovered from the pond), so thirty-eight does not show the true mortality this 

 year, that is, tbe mortality due to the ill-effects of detention in the pound or pond. 

 The loss this year must be reduced to twenty, because eight of the thirty-eight were 

 poisoned by the accidental use of red paint on the paddles in one of our hatching 

 boxes, and ten others died in the course of transportation to the pound. The real 

 loss, therefore, this year is only 6 per cent of tbe total, whereas, the loss on last year's 

 numbers (if no more can be found in the pond) was nearly 20 per cent. The greatly 

 decreased mortality this season is, undoubtedb', due to tbe great care exercised by 

 the department in collecting, feeding, and distributing them, and the shorter deten- 

 tion period in the pond and pound. No one, who appreciates the facts, will advocate 

 the retention of lobsters in either pond or pound for more than a few months at a 

 time. 



EGG-LAYING. 



Egg laying at Long Beach this season had two jjeculiarities. The first was that 

 about half the females extruded only a few hundred eggs in place of many thousands, 

 and the second was that the eggs on probably SO per cent of the mothers were unferti- 

 lized. 



In explanation of the former fact (noticed last year also) we at first assumed that 

 the mothers ha4 been interrupted in the act of egg-laying by being dipped up in the 

 net. Subsequent facts, however, showed that this was not the case, because, when such 

 lobsters were confined in crates or cars for a few weeks, the number of eggs was never 

 increased. Secondly, when (as happened on a few occasions) such a lobster died, 

 post mortem examination showed that the beast had extruded all the ripe eggs in her 

 ovaries, excepting perhaps half a dozen or so. This great reduction from the full 

 complement of eggs had to be explained on some other grounds. As this peculiarity 

 in egg-laying was limited, so far as the writer can remember, to females which had 

 spent the winter in the pond or pound, the reduction in the number of eggs would seem 

 to be due to the unfavourable conditions under which the animals had lived through- 

 out the winter — crowding in a small compartment, lack of adequate food, excessive 

 growth of algfe upon them, and the uncongenial mud of the bottom. In illustration 

 of this subject, the following facts may be quoted. In one compartment of the pound 

 were fifty females which had hatched their eggs in the summer of 1914 and been 

 retained in the pound all winter. Whether they had extruded eggs last autumn and 

 lost them during the winter or early spring is not known, but, at any rate, they were 

 all found without eggs on April 8, 1915. On July 19 an examination of the 50 

 resulted, as follows : — 



22 had no eggs on them. 



21 had new eggs on them, but none with the full complement. Within a week 4 of these 

 21 had lost the few eggs which they had. 



1 only had a full complement of eggs. 



2 had died. 



1 male only was present throughout the winter with these females. 



3 were unaccounted for. 



It is probable that few if any of the eggs carried by these twentyf-one females 

 were fertilized, because there was only one male present in the enclosure to mate with 

 the fifty females. It happened, unfortunately, at the time of this examination that 

 the rearing apparatus absorbed all my attention, and, consequently, no examina- 

 tion of the eggs was made to see whether they were fertilized or not. Nor must it be 

 supposed that the loss of eggs by four of these females out of the twenty-one was the 

 only instance of the kind which came under our notice this season. On another 



