14 MOUTH OF BUTTERFLIES AND MOTHS. 



would appear very doubtful. The principal modifica- 

 tions consist in the elongation of the tongue, and of 

 the labial palpi and maxillae which form its sheath ; 

 and besides these the maxillary palpi are so greatly 

 reduced in size, as to be scarcely perceptible in many 

 cases without a most careful examination. An in- 

 crease in some parts, and a diminution of others, are 

 therefore the changes for which we must look in our 

 investigation of the truly suctorial mouths. These 

 are of three principal kinds, of each of which examples 

 have been referred to above. 



In the Butterflies and Moths the sucking organ 

 consists of a long curled tube, which reposes between 

 a pair of hairy cushions projecting from the front of 

 the head. In this their natural state we should have 

 as great difficulty in discovering the nature of these 

 organs, as in recognizing the features of some well- 

 known friend recently fallen a victim to the fashion- 

 able epidemic of hair ; but on getting rid of these ob- 

 structions, the difficulties to a great extent vanish. 

 We then find that the hairy cushions are jointed 

 palpi, attached by their bases to a small lower lip, and 

 by a diligent search we may discover the representa- 

 tives of the mandibles and labrum in the form of three 

 minute processes above the base of the spiral trunk. 

 The latter, which would appear to be the most un- 

 accountable organ of the whole, is really formed out 

 of the two maxillae, the basal portions of which, 

 although small, exhibit nothing remarkable in their 

 structure, whilst the tips are produced into a pair of 

 long wrinkled tubes. Each of these tubes is furnished 

 along the entire length of its inner surface with a pair 

 of ridges, which fit together exactly, and thus the two 

 maxillae adhere together to form a single organ with 



