THE SCARCER FISHES OF THE ABERDEEN MARKET 61 



Let us first of all consider these records simply from the 

 point of view of seasonal distribution, according to the 

 months : 



The Sturgeon has been got off our coasts in every month 

 of the year. But it is most abundant in the spring and early 

 summer, about April and May, and least so in the autumn, 

 from August to October. When we "smooth" our total 

 numbers (by the simple statistical device of adding to each 

 the number before and after it) we obtain a very even series, 

 rising to a maximum in the month of May, and falling 

 gradually to a minimum in September (Fig. 1). 



Jan Feb. Mar. Apr. May June July Aug Sept. Oct. Nov. Dec. Jan. 



FlG. I. Seasonable Distribution of the Sturgeon, from Aberdeen and 



other Records. 



This maximum in spring and early summer coincides 

 with the season when the Sturgeon is proceeding towards, 

 or preparing to ascend, the rivers to spawn ; and it is hence 



