144 MUNSON. [Vol. XV. 



ovary, and the eggs, after they enter on the period of 

 growth. 



It is known from the observations of Lockwood, which I can 

 fully confirm, that the young animal moults more frequently in 

 its earlier than in its later stages. This seems probable from 

 the observations related in the chapter on the natural history, 

 where it was stated that the apparently grown soft-shelled 

 specimens were found, on examination of the ovary, not to 

 have any mature eggs in the ovarian tubes ; and that animals of 

 an equal size, having moulted earlier, were in a similar condition. 

 Histological e.xamination of the ovaries of these animals showed 

 that no egg had been discharged from the follicles, this being 

 an easy matter to determine. 



It was also stated that animals having mature eggs in the 

 ovarian tubes always had hard shells, which was also true of 

 all those females observed at Woods Holl during the spawning 

 season. 



These observations seem to show that the moulting is not a 

 phenomenon in any way connected with the season of the year, 

 but that it is intimately connected with the phenomena of 

 growth. 



Now, it having been shown that the young of Limulus moult 

 much more frequently than the adult animals, and that with 

 each moult the young animal increases greatly in size, it is 

 extremely probable that the animal increases in size much more 

 rapidly in the earlier than in the later periods of existence. 



From the comparative size of the first-formed diverticulum, 

 and its contained egg in the seven-inch animal and the later 

 stages, the same retardation of growth from earlier to later 

 periods, observed in the animal, seems to hold good also 

 in regard to the growth of the ovary and the eggs contained 

 in it. 



This may explain the apparent contradiction in the correla- 

 tion of growth, which at first sight seems to present itself in 

 the case of those eggs that are still growing after the period of 

 sexual maturity is reached. For while the oocyte first formed 

 is discharged from the follicle at the first period of sexual 

 maturity, the one which is just formed in an animal eighteen 



