226 



DE. G. H. FOWLEE — BISCATA]N^ PLANKTON : 



Bumber available, the tendency of tbe ordinates to form a curve of frequency at each 

 stage is noticeable, though the shape and area of the curve is entirely guesswork in the 

 present instance *. When the numbers are greater, and a greater range of variation is 

 found in each curve, the extremes of the curve may respond to the same growth-factor 

 as the means. Even here, in the more numerous females, 0'6xl'50=0'9; 0'9xl*56 

 =1"4 ; 1'4 X 1'56= 21, that is to say, the shortest observed length at each stage multiplied 

 by the growth-factor gives the shortest at the next stage: and 0'7xl'56=l-0; 

 1-0 Xl'56 = 1-56 (1-6) ; l-6xl"56=2-49 (25), that is to say, the same is approximately 

 true for the greatest length at each stage. 



Fix. A. 



MM 



Literature. — A list of the most important memoirs was given in Professor Miiller's 

 * Valdivia ' Report. Two have appeared since that date : V. Vavra, ' Die Ostracoden 

 der Plankton Expedition, 1906 ' ; and C. Juday, " Ostracoda of the San Diego Region," 

 Univ. Calif. Public, Zool. vol. iii. no. 2, pp. 13-38 (1906), as well as Miiller's own 

 Reports on the Ostracoda of the ' Siboga ' and ' Belgica ' expeditions. 



* In this explanatory instance of imbricata alone, an imaginary curve of frequency has) been drawn over the 

 ordinates. In subsequent diagrams of other species, the ends of the ordinates have been connected by dotted straight 

 lines, rather in order to show which of them can be grouped together as belonging to the same stage, than with 

 any mathematical meaning. 



