Rate of Growth in Gobi us minutus. 221 



paper by Holt and Byrne * to which reference has already 

 been made : — 



" Probably the life of this species {G. minutus) seldom 

 extends over two winters; a specimen kept in a tank at 

 Plymouth attained a length of 76' mm., and was fully adult 

 about a year after the probable date of hatching." 



In the present inquiry no example of such rapid growth 

 can be quoted, but the large size of the specimen described 

 above may have been in part due to the effects of a compa- 

 ratively high temperature and plentiful food-supply. At 

 the same time there are six specimens in the collection 

 captured near St. Andrews early in September, and therefore 

 approximately 15 or 16 months old, which have an average 

 length of 75 mm., and the largest is 80 mm. Most of the 

 adult fishes appear to die off during the winter following their 

 breeding-season, for only two such occur in the large collec- 

 tion at my disposal from November to March. The two 

 adult specimens referred to were captured near St. Andrews 

 towards the end of January, and average 78 mm. An inter- 

 esting experiment might have been made if these gobies had 

 been kept alive in a tank; but as one of them had already 

 reached 80 mm., which is the normal limit of growth for the 

 species, it is more than probable that they were Hearing the 

 end of their natural life. 



Statistical Tables and their Graphic Representation. 



All the bottles of gobies in the two collections were first 

 arranged in chronological order, according to the dates on 

 which the fishes had been taken. Then the numbers in each 

 catch were counted, aud the average length, inclusive of the 

 caudal fin, noted. It seemed more than possible that the rate 

 of growth and the maximum size attained by individual fishes 

 might vary in different areas. Accordingly the results were 

 divided into four groups, in relation to the areas in which the 

 gobies were taken. Thus, four statistical tables are formed, 

 I. St. Andrews Bay; II. Forth Area; III. Clyde Area; 

 IV. N.W. Area (including Aberdeen Bay and the Moray 

 Firth). A word must be said with regard to the first column 

 in the tables headed " Date of capture/' It is apparent that 

 an arrangement of dates in which the years are not taken into 

 account must be defective \ but it was considered that a better 

 end would be served by arranging the fishes according to the 



* Op. cit. p. 53. 



