NO. r, I -J COLOR SENSE OF THE HONEY-BEE 



is accepted and the apetalous orders be regarded as primi- 

 tive it does not support the thesis that small, green 

 flowers are at no disadvantage in attracting insects he- 

 cause of their inconspicuousness. That reduction and 

 change from entomophily and conspicuousness to ane- 

 mophily and inconspicuousness has occurred repeatedly 

 in widely separated families is not questioned by any cco- 

 logist or taxonomist. This is illustrated by the genera 

 Artemisia, Ambrosia, etc., among the Composite; in 

 Ricinus of the Euphorbiaceae ; probably also in the family 

 Juncaceae, and in species of Thalictrum, Fraxinus, San- 

 guisorba and Poterium. The evidence supplied by the 

 pliylogeny of green flowers is wholly in favor of the value 

 of color contrast for gaining the attention of insects. 



Approaching the problem from another direction, the 

 Rev. George Henslow in his work on the self-fertiliza- 

 tion of plants finds that "inconspicuous flowers are al- 

 most invariably self-fertilizing, or else inconspicuous." 



There are several reasons why inconspicuous flowers are not likely to 

 be intercrossed by insects: (1) Their unattractiveness ; (2) the absence 

 of honey-secreting organs; (3) the want of scent; (4) they frequently 

 do not expand, or at most remain half open, especially in cold or inclem- 

 ent weather, while perfectly cleistogamic flowers are, of course, never 

 open; (5) their structure sometimes would seem absolutely to prevent 

 the ingress of insects (such appears to be the case with Polygonum 



closed, and with many others. 



He regards existing inconspicuous forms not as primi- 

 tive, but as derived from conspicuous progenitors, which 

 in turn owed their origin to the selective influence of 

 insects. 9 



It has been shown that Plateau's conclusion is not sus- 

 tained either by the pliylogeny and distribution or by the 

 ecology and manner of fertilization of inconspicuous 

 flowers, which have almost universally been compelled to 

 adopt anemophily or autogamy. In the few exceptional 

 cases there are present other allurements, as odor and 

 nectar, which sooner or later attract insects; but this 



