28 



THE AMERICAN BOTANIST 



parts are hardy enough to persist until a new frond is spread. 

 This seems hardly difference enough to entitle such a plant to 

 be considered a distinct species if the plant in question is to 

 be called a species, it should, according to Tidestrom, be called 

 Botrych'mm ciciitarium. The writer is of the opinion, however, 

 that it will ultimately find a place in fern lists as Botrychium 

 Virgimamm- var. dichromim or B. V. var. cicutarium. 



Color-Blind Bees. — The sun sends to us across the 

 boundless regions of space, a vast number of waves of different 

 length, but in all this number the human eye can distinguish 

 barely an octave — some seven groups which we know as red, 

 orange, yellow, green, blue, indigo and violet rays. Below the 

 red rays are other ra3^s w^hich, though invisible, may be de- 

 tected by proper means. Similarly beyond the violet rays are 

 other ra3^s that affect the photographer's plate, but which, so 

 far as the eye is concerned, might as well not exist. In work- 

 ing out our theories of vision it is possible that we have not 

 taken account of all the facts. With regard to insects and 

 flowers, for instance, it is quite possible that the insects can see 

 very different colors in the flowers from those we perceive. 

 As a matter of fact, it is now known that bees are color blind 

 for some of the colors we can perceive. A German scientist 

 has recently shown that bees cannot distinguish between red 

 and black. Experiments seem to show, also, that these insects 

 are insensible to certain shades of blue-green which are comple- 

 mentary to red. Blue and yellow, however, are easily recog- 

 nized. This latter fact probably accounts for the reported fond- 

 ness of bees for blue flowers. In the matter of the preferences 

 of bees for color, however, one should not proceed too rapidly. 

 It must not be forgotten that the bee does not depend entirely 

 upon color in hunting food. The sense of smell is know^n to be 

 well developed and the bee doubtless usually '^follows her 

 nose." Xectar-yielding- flowers, though concealed from sight, 

 are readily found by bees and so are other flowers from which 

 the showy petals and other parts have been removed. 



