DISPERSION OF POLLEN BY ANIMALS. 



157 



joint of the maxillary palp is lengthened to an extraordinary extent, and its inner 

 surface is beset with stifF bristles and can be rolled up like a trunk (see fig. 240^). 

 It is used to seize the pollen, to conglomerate it into a ball and afterwards to hold 



Fig. 240.— Transport of Pollen by Egg-laying Insects. 



' Branch from the inflorescence of Yucca Whipplei; the middle flower open, that beneath it was open the previous night and ia 

 now closed again, the rest of the flowers in bud. 2 Single flower of the same plant visited by a moth of the species Pronuba 

 yuccasella ; the three front perianth-leaves removed. 8 Stigma of Yucca Whipplei. * Pronuba yuccasella flying to a flower 

 of Yucca Whipplei. s Head of Pronuba yuccasella with a hall of pollen held by the coiled maxillary palp. ^ Twig with inflores- 

 cence of Ficuspumila ; the urn-shaped Inflorescence (or synconium) cut through longitudinally. ? Single female flower from 

 the bottom of the synconium of Fieus pumila. 8,9 Stamens of the same plant from the upper part of the synconium. 

 It* Synconium of Ficus Carica full of gall-flowers produced by Blastophaga, cut through longitudinally ; near the mouth of 

 the cavity is a fig-wasp {Blastophaga grossorum) which has escaped from one of the galls, n Synconium of Picus Carica 

 full of female flowers, cut through longitudinally; near the mouth of the cavity are two Fig-wasps, one of which has 

 already crept into the cavity whilst the second is about to do so. 12 Male flower, is Long-styled female flowers of Ficus 

 Carica. 1* GaU produced from a short-styled gall-flower, i* Blastophaga grossorum escaping from a gall, i^ A liberated 

 Blastophaga. " The same magnified. 1, 2, \ a, 10^ 11, 16, natural size ; 8x2; s x 20 ; ^ ^^ 9, 12, u x 5 ; ", ", i^ x 8. 



i. In a very short time a moth collects by its means a ball of pollen, which is held 

 5y the roUed-up palpi close underneath the head and resembles a great crop. Laden 

 ivith this lump of pollen, which is sometimes three times as large as its head, the 



