Vision in Insects, 6i 



The compound eyes are motionless, but from their size 

 and sub-spherical shape, they give quite a range of vision. 

 It is not likely that they are capable of adjustment to 

 accord with different distances, and it has been supposed, 

 from the direct darting flight of bees to their hives, and 

 the awkward work they make in finding a hive when 

 moved only a short distance, that their eyes are best suited" 

 to long vision. 



Sir John Lubbock has proved, by some interesting 

 experiments with strips of colored paper, that bees can 

 distinguish colors. Honey was placed on a blue strip, 

 beside several others of various colors. In the absence of 

 the bees he changed the position of this strip, and upon 

 their return the bees went to. the blue strip rather than to 

 the old position. Our practical apiarists have long been 

 aware of this fact, and have conformed their practice to 

 this knowledge, in giving a variety of colors to their hives. 

 Apiarists have frequently noted that bees have a rare fac- 

 u'.tv of marking positions, but, for slight distances their 

 sense of color will correct mistakes which would occur if 

 position alone were their guide. Yet I believe more has 

 been made of this matter of color than truth will war- 

 rant. Lubbock's experiments prove that ants and wasps 

 also distinguish colors. ' This is doubtless true of all insects 

 that love sweets and are attracted by flowers. I have 

 noticed a curious blunder made by bees in case of two 

 houses which are just alike, but five rods apart. Honey 

 placed on one porch is scarce found by bees before the cor- 

 responding porch of the other house will be swarming 

 with bees also, though no honey is near it. The bees are 

 simply fooled. This experiment has been tried several 

 times, so there can be no mistake. It shows that sight, 

 not mere position, nor yet odor, is guide, even at long dis- 

 tances. 



Within the head is the large brain (Fig. 17), which will 

 be described as we come to speak of the nervous system. 

 There are also chitinous bars and braces within, which serve 

 greatly to strengthen this portion of the insect. 



