THE ORCHIDS OF NEW ENGLAND. 63 
“All dull yellow (dirty-yellow, brownish-yellow, yellowish- 
white) flowers,” says Muller,* giving a long list of genera which 
includes Neottia, “are entirely or almost entirely avoided by 
beetles; closely allied white flowers are visited by beetles, more 
or less to their injury ; and brightly colored flowers, even though 
they are scentless and offer no honey, or none that is accessible, 
attract beetles in numbers. If (as he supposes) beetles are only 
or mainly attracted to flowers by bright colors, dull yellow must 
be an advantageous color for plants with freely exposed honey, 
protecting them from these injurious guests. And the fact that 
dull yellow colors only occur in flowers with exposed honey 
lends support to this view.” Speaking in another placet of 
the effect of conspicuousness in inducing insects’ visits, he says: 
“« . . , those insects whose bodily organization is least 
adapted for a floral diet are also least ingenious and skilful 
in seeking and obtaining their food, so that with anthophilous 
insects intelligence seems to advance parz passu with structural 
adaptation,” hence, “short-lipped insects, little or not at all 
specialized for a floral diet, can usually only find fully exposed 
honey, such as Listera (and others) afford; honey still easily 
accessible but not directly visible to them is passed by.” 
He says again: “Insects in cross-fertilizing flowers endow 
them with offspring which, in the struggle for existence, van- 
quish those individuals of the same species which are the off- 
spring of self-fertilization. The insects must, therefore, operate 
by selection in the same way as do unscientific cultivators 
among men who preserve the most pleasing or most useful 
specimens, and reject or neglect others. In both cases, selec- 
tion in course of time brings those variations to perfection 
which correspond to the taste or needs of the selective agent.” 
As insects became more skilful and intelligent, flowers became 
more varied in color, more complicated in structure, etc. “ The 
* Fertilization of Hlowers, p 574. + Page 571. 
