THE IMPOVERISHMENT OF THE SEA. 17 



experiments, the average number of dabs taken from the Forth 

 considerably exceeded the corresponding number from the Bay in six 

 months out of the twelve. It is consequently not surprising, if, owing 

 to the increased influence of the Forth on the averages for the second 

 quinquennial period, there should be displayed a considerable number 

 of months in which the combined averages show an apparent increase 

 in the abundance of dabs. 



I conclude that the figures recently submitted by Dr. Fulton in his 

 new summary of the results of the Garland's experiments by no means 

 re-establish the conclusions set forth in his original review. It appears 

 to me that, in consequence of the irregularity of the Garland's opera- 

 tions, it is quite impracticable to set up well-founded conclusions upon 

 a basis formed by combining the figures for the Forth and Bay. One or 

 other of these areas, under the conditions of the experiments, must 

 unduly bias the averages, and unless an equivalent proportion is main- 

 tained between the monthly surveys in the two areas in each period, the 

 resultant differences between the quinquennial averages must necessarily 

 be fallacious. 



Nevertheless, while going even a step further than Professor Mcintosh 

 in his criticism of the methods by which the results of the Garland's 

 experiments have been set forth, I am quite unable to follow the 

 Professor in his condemnation of the experiments themselves, which 

 would appear from internal evidence to have been well designed and 

 executed. The irregularity of the surveys in the earlier years is much 

 to be regretted, and demands more than ordinary care to be bestowed 

 upon the analysis of the results. But from the impartial and critical 

 examination which I may claim to have made of the published records 

 of the experiments, I am satisfied that the experiments have been 

 largely successful in throwing light on the problem which they were 

 designed to elucidate, in spite of the unfortunate errors of method with 

 which the conclusions have been associated. 



It appears to me, under the circumstances of the case, that Dr. 

 Fulton's method of averaging the figures for two quinquennial periods 

 and for the different months of the year is perhaps the best method to 

 adopt in order to obtain a general view of the changes wrought during 

 the ten years of prohibited trawling; although, in view of the small 

 number of surveys made during the first two years and their greater 

 frequency during the last five years, there would be certain advantages 

 in dividing the decade into a first period of six years and a second 

 period of four years. This alternative method would have the effect 

 of increasing the number of monthly surveys in the first period, and 

 thus of rendering valid certain of the monthly averages which, in the 

 quinquennial period adopted, are based upon too small a number of 



NEW SERIES. — VOL. VI. NO. 1. B 



