GERMINAL SELECTION. 21 



That exempt diurnal butterflies should be colored 

 on the upper and under surfaces alike, and should 

 never resemble in the attitude of repose their ordinary 

 surroundings, is intelligible when we reflect that it is 

 a much greater protection to be despised when dis- 

 covered than to be well, or very well, but never abso- 

 lutely, protected from discovery. 



It has been so often reiterated that diurnal butter- 

 flies, as a rule, are protectively colored on the under 

 surfaces, that one has some misgivings in stating the 

 fact again. And yet the least of those who hold this 

 to be a trivial commonplace know how strongly its 

 implications militate against the inner motive and 

 formative forces of the organism, which are ever 

 and anon appealed to. No less than sixty-two genera 

 are counted today in the family of diurnal butter- 

 flies known as the Nymphalidse. Of these by far the 

 largest majority are sympathetically colored under- 

 neath, that is, they show in the posture of rest the 

 colorings of their usual environment. In a large 

 number of the species belonging to this group the 

 entire surface of the hind wings possesses such a 

 sympathetic coloration, as does also the distant apex 

 of the fore wings. Why? The reason is obvious. 

 This part only of the fore wing is visible in the atti- 

 tude of repose. Here, then, — as a zealous opponent 

 of the theory of selection once exclaimed, — there is 

 undoubted "correlation" between the coloring of the 

 surface of the hind wing and of the apex of the fore 

 wing. Correlation is unquestionably a fine word, but 

 in the present instance it contributes nothing to the 

 understanding of the problem, for there are near rela- 

 tives and often species of the sartie genera in which 

 this correlation is not restricted to the apex of the 



