32 



A. E. HEFFORD. 



From this evidence we can merely state that the average size of the 

 egg shows an increase in the order in which the species are enumerated 

 above, but the difficulty arising from overlapping is sufficiently formid- 

 able, seeing that the largest size for G. minutus may be larger than 

 that of the smallest whiting. 



The size of the newly hatched larva shows variation, which may to 

 some extent be taken as a guide to the species, but on this point, to an 

 even greater degree than is the case with regard to the egg, the data 

 hitherto available are very scanty and afford little satisfactory informa- 

 tion. With some degree of certainty we may take it that the 

 G. minutus larva is the smallest, but no measurement of tlie product 

 of artificial fertilization is on record. Holt (lib) records as G. minutus 

 a larva of 2'75 mm. length hatched from a pelagic egg of 1"07 mm. 

 The G. luscus larva is probably bigger, and that of G. merlangus is 

 certainly bigger still. Ehrenbaum (5d, pp. 234 and 238) gives ca. 3 mm. 

 or somewhat smaller for the former and 3*2 to 3*5 mm. for the latter 

 species. G. poilachius is so far too imperfectly known for us to state 

 anything as to its larval dimensions. Holt (lid, p. 141) ascribes to 

 this species certain pelagic ova of 1'40 to 1*45 mm. diameter taken in 

 February, and mentions that the larva was 4-2 mm. long and had black 

 pigment only. There seems to me to be little doubt as to the correct- 

 ness of this identification, and it seems probable that further investiga- 

 tion of the eggs and larvae of this species will prove them to be larger 

 in general than those of G. merlangus. 



The dimensions of all the Gadus eggs measured during the season 

 are as follows : — 



Fehruary 



April and 

 early May 



June-AwiHst ^^ 



JNo. 01 eggs 1 



