Trans. Acad. Sci. of St. Louis. 



1860 



1865 



1870 1875 1880 1885 



Pig. 3. Persistence. 



1890 



1895 



1900 



the growth was more rapid; for the last year or so we have had about 250 

 members. 



Fig. 3 shows the persistence of members, that is to say, how many 

 members who were elected in any one year are at present members of 

 the Academy. There are eight members still with us who were members in 

 the first two years. We have no members in the Academy who were elected 

 to membership during the period from 1856 to 1870. Of those elected from 

 1870 to 1890 there are a few, but not a large number. In 1891 there was a 

 considerable increase in the membership, and 61 persons elected in that year 

 are still members. From 1891 to 1897, there were comparatively few elected 

 who are still members. 



From these curves it appears that the most active periods in the Academy's 

 growth have been from the beginning of 1856 to, say, the end of 

 1860 and from the beginning of 1891 to the end of 1894. The first 

 of these periods corresponds to the enlistment of practically all the available 

 men in St. Louis at that time, and the second, which really extends up to 

 the present time, although for several years there was a period of relaxation, 

 represents the response to efforts made by the members of the Academy in 

 recent years to interest professional and business men in the affairs of the 

 Academy. The curves also show that if this second period of vigorous 

 growth had not taken place, we should now hardly have 100 members to 

 carry on the Academy's work; 82 per cent of the members who are now 

 enabling the Academy to do its work have been elected since 1891. 



No doubt a complete discussion of these curves might bring out many 

 interesting facts, and, were the data sufficient, it might be worth while to 

 determine the curves, which would indicate the life of the Academy with 

 greater accuracy ; but without entering into any mathematical discussion of 



