of the, Fishery Board for Scotland. 



147 



nitrogen was easily obtained. If the nitrogen given in the Tables be 

 multiplied by 6*35, the amount of albumin is roughly estimated. 



As I shall point out later, it was important, also, to find out whether, 

 during maturation, the phosphorus was increased in amount, and especi- 

 ally if the ratio between the nitrogen and the phosphorus was dififerent 

 in the unripe and ripe ova. I shall only include those analyses in the 

 following Table which have been made more than once : — 



Pelagic Ova N and P in Milligrammes. 





Immature. 



Mature. 



N. 



p. 



N. 



p. 



Plaice, 



•022 



•0030 



•0270 



•0046 



Whiting, 



•0026 



•00012 



•0040 





Haddock, 



•0095 



•0013 



•0146 



•0029 



Cod, .... 



•0099 



•0012 



•015 



•0026 



Brill, .... 







•0233 



•0033 



Flounder, 







•0080 



•0010 



Ling, .... 







•0082 





Saithe, 







•004 



•00018 



Katio between Nitrogen and Phosphorus in the Immature and 

 Mature Ova. Nitrogen = 1. 





Immature. 



Mature. 



N. 



p. 



N. 



P. 



Plaice, 



1 



•136 



1 



•170 



Whiting, 



1 



•046 







Haddock, 



1 



•136 



1 



•198 



Cod, .... 



1 



•121 



1 



•173 



Brill, .... 







1 



•141 



Flounder, 







1 



•125 



Ling, .... 





z 







Saithe, 







1 



•045 



During maturation there is an absolute increase in the nitro- 

 gen present in the ovum, probably due to a passage inwards of 

 albumin in some form or other. What is especially noteworthy, how- 

 ever, is the marked increase in phosphorus, which is much more distinct 

 than the nitrogen increase. As we shall see afterwards, this is probably 

 due to the passage inwards of an organic phosphorus-holding body, 

 selected by the tunica granulosa cells at the commencement of matura- 

 tion from the ovarian fluid outside. The nitrogen percentage may be 

 stated as albumin by multiplying by 6-35. 



