LUTHER BURBANK 



considering the unrevealed nature of the stimulus 

 associated with odors, to adopt Professor Loeb's 

 cautious phrasing and speak of the sense through 

 which insects are guided to odoriferous objects as 

 "chemical irritability." 



The fact that a bee is able to travel in a straight 

 line backward and forward between its distant 

 hive and the flower bed or the apple tree from 

 which it is harvesting, even though the distance be 

 a matter of miles, suggests the possession of organs 

 of sense of a far more delicate character than our 

 olfactory nerves. 



It is hardly probable that vision is an important 

 aid in these long-distance flights; for Professor 

 Loeb's experiments have led him to infer that the 

 dioptric apparatus of insects is very inferior to the 

 human eye. Moreover the flowers would scarcely 

 find it necessary to put out expansive corollas and 

 deck themselves in gaudy colors if their signals 

 were meant for creatures having very acute vision. 



In point of fact, the complex multiple eye of 

 the insect, devoid of any such adaptive apparatus 

 for focusing as the lens of the mammalian eye, 

 does not suggest acuteness of vision, but rather a 

 more or less vague appreciation of large masses 

 of color. 



The recent experiments of Dr. Charles A. 

 Turner, of the St. Louis Academy of Science, have, 



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