104 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



the two series of statements. If, however, we remove the 

 additional observations dealt with by Mr. Dahl, and which 

 were apparently not a part of the joint enquiry agreed 

 upon, some facts remain in common, although -they may 

 be interpreted in different ways. For example, Dannevig 

 shows that in 1903, before his Flodevigen larvae were 

 liberated, the Sondeled Fjord yielded 426 cod larvae (to 

 over 100 hanls of the seine =4 per haul), while the two 

 following years (after the planting of the fry), averaged, 

 gave 1,328, or about 13 per haul. Removing the July- 

 August observations, which do not appear in Dannevig's 

 experiments, these numbers agree with what is shown in 

 Dahl's table, and indicate an increase to about three 

 times the amount. In the case of the Hellefjord, where 

 smaller numbers were dealt with, the correspondence 

 of results is not so clear, and some further explanation 

 is perhaps necessary; but, averaging both localities, 

 Dannevig shows the increase after planting to about 

 double the quantity, which is represented graphically in 

 his diagram. Captain Dannevig, of course, attributes 

 the increase to the liberation of the artificially hatched 

 larvae, while Dahl from his additional observations with 

 tow-nets, &c, comes to the conclusion that the cod eggs 

 and larvae naturally present are so affected in their 

 abundance and distribution by currents in the water 

 which vary from year to year, that the fry added can have 

 no appreciable effect, and that such increases or decreases 

 as may be noted from year to year are due to natural 

 reproduction and hydrographic influences. The impres- 

 sion produced by reading these two papers is, I think, 

 that the observations are still too few to lead to any sure 

 conclusions; but it may be useful to point out that, even if 

 Dahl's interpretation is correct, it does not follow that 

 Dannevig's operations are useless. If the addition of 50 



