INSECTS. 305 



their adaptation than the antennae of the moth, represented in Plate 

 IX., No. 1, with tliin finger-like extremities almost supplying the 

 insect with a perfect and useful hand, moved throughout its extent by 

 a muscular apparatus, the whole being of a feathery construction ! 

 The tongue. No. 2, for the purpose of dipping into the interior of the 

 flower and extracting the honey, is endowed with a series of muscles : 

 an enlarged view of a portion of the same is seen at No. 3. 



The inconceivably delicate structure of the maxillae or tongues (for 

 there are two) of the butterfly, rolled up like the trunk of an elephant, 

 and capable like it of every variety of movement, has been carefully 

 examined and described by Mr. Newport. " Each maxilla is convex 

 on its outer surface, but concave on its inner; so that when the two are 

 approximated, they form a tube by their union, through which fluids 

 may be drawn into the mouth. The inner or concave surface, which 

 forms the tube, is lined with a very smooth membrane, and extends 

 throughout the whole length of the organ ; but that each maxilla is 

 hollow in its interior, forming a tube ' in itself,' as is generally de- 

 scribed, is a mistake ; which has doubtless arisen from the existence of 

 large trachse, or breathing-tubes, in the interior of each portion of the 

 proboscis. In some species, the extremity of each maxilla is studded 

 externally with a great number of minute papillae, or fringes — as in the 

 Vanessa Aialanta — in which they are little elongated barrel-shaped 

 bodies, terminated by smaller papillae at their extremities." Mr. New- 

 port supposes that the way in which the insect is enabled to pump up 

 the fluid nourishment into its mouth is this : " on alighting on a flower, 

 the insect makes a powerful expiratory effort, by which the air is ex- 

 pelled from the interior air-tubes, and from those with which they are 

 connected in the head and body ; and at the moment of applying its 

 proboscis to the food, it makes an inspiratory effort, by which the 

 central canal in the proboscis is dilated, and the food ascends it at the 

 same instant to supply the vacuum produced j and thus it passes into 

 the mouth and stomach : the constant ascent of the fluid being assisted 

 by the action of the muscles of the proboscis, which continues during 

 the whole time that the insect is feeding. By this combined agency 

 of the acts of respiration and the muscles of the proboscis, we are also 

 enabled to understand the manner in which the humming-bird sphinx 

 extracts in an instant the honey from a flower while hovering over it, 

 without alighting ; and which it certainly would be unable to do, 

 were the ascent of the fluid entirely dependent upon the action of the 

 muscles of the organ."* 



* Cyclop, Anat. and Physiol., article "Insecta." 

 X 



