64 ROMANCE OF THE INSECT WORLD CHAP. 



partly concealed and defended between the labial 

 palps. It can be brought forward in an instant, 

 straightened out, and darted downwards in obedience 

 to the bidding of its owner. In regard to length 

 it varies in the different genera and species, show- 

 ing all degrees from the proboscis of the Bomby- 

 cidae, that take little or no food, in which it is almost 

 imperceptible, to that of Sphinx ligustri and the 

 Humming Bird Hawk Moth of South America (Macro- 

 glossa titati), the trunks of both of which are about 

 two inches long. In butterflies and many of the 

 Noctuidae they are about the same length as the 

 body. The Sphingidse are remarkable for not alight- 

 ing on the flower that they propose to rob, they poise 

 on the wing before it, and rapidly dip into its well- 

 like honeyed cups, without crumpling a petal. 

 Having extracted its sweetest contents, they hasten 

 away on their violent flight to another blossom. 



The manner in which the honey is conveyed by the 

 trunk to the mouth has been explained to be by 

 capillary* attraction. This opinion is probably in- 

 correct, since the ascent of the fluid along the tube is 

 not gradual and regular, as would be the case were it 

 occasioned by this action. The liquid is as it were 

 pumped from the flower, sometimes in full stream for 

 one or two seconds ; then the motion falls off and 

 becomes slower and slower, indicating distinct in- 

 tervals between each draught or ascent of the fluid. 

 The phenomenon appears to be due partly to the 

 undulations and contractions of the sides of the tube 

 occasioned by the action of its transverse muscles, 

 which continue in action so long as the insect is feed- 



