22 GENERAL REMARKS ON THE EGGS OF MARINE FISHES. 



presented by the ocean. The struggle can be none the less 

 keen though in this case the agencies of destruction are 

 probably more of a physical than an organic nature. Before 

 leaving this part of the subject it is well to note that the 

 demand of the succeeding generation upon its parents is the 

 same in each case : — for the cod, in return for the entire neglect 

 of its young from the moment of oviposition, has to meet the 

 enormous demands upon its organisation which are caused by 

 the production and ripening of the huge number of eggs which 

 are necessary to maintain the balance of nature, demands 

 so great as to render the parent-fish almost unfit for food when 

 in the spent condition. 



This utilization of the tissues of the parent-fish during the 

 growth of the roe is a subject that has recently attracted much 

 attention in connection with the salmon, since it has been 

 found that peculiar chemical changes take place in the muscles 

 under these conditions. Dr Noel Paton, with the aid of 

 Dr GuUand and others in Edinburgh, is at present engaged in 

 an extensive inquiry of this nature on the salmon, a fish 

 in which the changes have important legal as well as physio- 

 logical bearings. We look forward to the publication of these 

 observations and also those of Dr Alex. Brown, on the salmon 

 of the Aberdeenshire rivers, with much interest. 



We also find that the fishes with pelagic eggs have a larger 

 projjortion of the female sex, whilst the reverse is the case with 

 fishes laying ' demersal ' eggs. Thus female gurnards are found 

 in the proportion of four to every single member of the 

 opposite sex, whilst the male gurnard appears to be slightly 

 smaller than the female. In the case of the haddock and 

 whiting the proportion is that of one male to two females; 

 while in the cod the number of each sex is much more equal, 

 about four males occurring to every five females. 



As regards the relative size of the different sexes, the 

 whiting, like the gurnard and all flat fishes, has a larger 

 female, whereas the male haddock and cod are slightly larger 

 than the females. 



In the ' pelagic ' fishes not only are the females more 

 abundant but the ovaries are much greater in bulk when 



