52 



THE COCKROACH I 



penetrate deep flower-cups, and hairy, so that pollen may stick 

 to it. When the proboscis is not in use it can be slid into the 

 men turn (M), while it and the mentum together can be drawn 

 out of the way downwards and backwards.* 



In the singular suctorial mouth of Moths and Butterflies we 

 observe, first of all, the great development of the maxillae. 



o 



Fig. 24. Mouth-parts of Burnet Moth. 



Lm 



Fig. 24 A. Diagram of Mouth-parts 

 of Moth. 



Each forms a half-tube, which can be accurately applied to its 

 fellow, so as to form an efficient siphon. In many species the 

 two halves can be held together by a multitude of minute 

 hooks.f At the base of each maxilla is a rudimentary palp 

 (Mxp). The mandibles (Mn) are also rudimentary and perfectly 

 useless. The labium, which was so important to the larva as a 

 spinneret, has disappeared almost completely, but the labial 

 palps (Lp) are large and evidently important. 



* An interesting account of the structure and mode of action of the Bee's tongue 

 is to be found in Hermann Miiller's Fertilisation of Flowers, where also the evolu- 

 tion of the parts is traced through a series of graduated types. 



t See Newport's figure of Vanessa atalanta (Todd's Cyc. , Art. Insecta), or Burgess 

 on the Anatomy of the Milk-weed Butterfly, in Anniversary Mem. of Boston Soc. 

 Nat. Hist., pi. ii., figs. 8-10 (1880). 



