180 EVENINGS AT THE MICROSCOPE 



tinct; and are moreover imperfect; for each wire (so to 

 speak) does not perform a complete circle, but only about 

 two-thirds of a circle, leaving a blank space; and the tips 

 of the wires end alternately in a fine acute point, and in a 

 rounded fork, like the prongs of a pitchfork. It has been 

 said that these tubes are modified trachece; but this fact 

 is by no means obvious to me; for so far from their being 

 connected with the general tracheal system, each of the 

 four main tubes originates in an open centre, and each 

 with an open extremity. I think it likely that they are 

 so many suctorial pipes, through which the fluid to be 

 drunk is pumped up, entering at their minute open tips, 

 and discharging itself into the central cavity, by the open 

 basal extremities of the main tubes. 



The most extraordinary modification of jaws, however, 

 is the long spiral tube which is ordinarily coiled up under 

 the face of a Butterfly or Moth, with which it pumps up 

 the sweet nectar of flowers. Many flowers have a deep 

 corolla, and most have the bases of their petals, where the 

 nectar lies, so far from the level of the surface that prob- 

 ing is necessary to reach it. Bees can enter tubular flow- 

 ers, and lick their bottoms; and even blossoms that are 

 closed, as the Snapdragon, they know how to force and 

 enter. But Butterflies, with their wide wings, incapable 

 of being folded, cannot enter flowers bodily, and there- 

 fore a peculiar apparatus is given them for robbing their 

 contents, as it were, at the doors. 



Nothing is easier than to examine this beautiful organ 

 with the naked eye; and much may be learned of its 

 structure by means of a pocket lens. You may thus see, 

 in a moment, that it forms a flat spiral of several coils, 

 like the mainspring of a watch ; that it runs off to a point, 



