92 



Piilcij — Some Jntcrirlaflons of Plants and Insects. 



portant .structures has not proceeded so far in Proiwlxi i/urni-'^etta 

 as in P. iiiaculnta, which pollinizes Yueea njJiipplei. Those not 

 familiar with the structure of Lepidoptera will hardly appreciate 

 the modifications to which I shall allude, however, without the 

 preliminary statement that the tongue in T7ei)idoptera consists 

 of two distinct parts (maxilbe) which are more or less concave 

 on their inner side and united at the l)()rders of the concave i)or- 

 tion by certain locking arrangements to form between them the 

 sucking tube. Now, while in most cases the two parts may be 

 relaxed and separated by force, in nature they are never so sepa- 

 rated, while the tip of the tongue is more or less acuminate and 

 the two parts here very firmly united. 



X /S" 



Fk;. 7. — I'lii'M I!A MACui.ATA ; a, tip of feiuale ubdouu'ii; bj o, basal joint ol' (iviixisiUir : 

 /.,/ ';, teriniiial Juint of ovipositor; of, oviduct; m p, max. palpus; in i, luaxillai-y teuta- 

 (de; f, tongue ; g.v, elaspers of male from side; (7/', claspers of male from behind — eu- 

 hu'gom',Mit indicated ; pr, front wings, showing arraugement of spots in two of the more 

 couiiuou forms, hair-lines .showing natural size. 



In ProimJxi i/nceasellec I had often noticed that the two part^ 

 became separated and in tact were almost always separated 

 toward the tip, thus suggesting a loss of function as a sucking 

 organ, l)ut otherwise the tongue is strongly developed, and, Avith 

 the exception of the weakness of the locking arrangement, not 

 particularly al)normal. In Prun.iiJ)a maealata, however (Fig. 7), 

 the two ])arts of the tongue are but very feebly united, and often 

 more or less disconnected, and are actually thickly covered with 

 minute hairs and more sparsely with longer spinous hairs, inter- 

 mixed ; they are also swollen and enlarged toward the base. The 

 import of this fact can best be conveyed to you by thestatenjcnt 



