215 



to NovtMiii.rr S. 1!»()4. nt whirli iMst .lato fcrty-sevtii lurfr.-t thiwcrs were 

 conntrd. Lonu' lu'tore Xoveiuher hravy iTost had endr.l all ius.Tt visits 

 and tlK. plnnt had l.eeii deiiendent on self-i,ollination for tVrtlli/.alion lor 

 a month. With f.ost c-ame some noticeable ehauges in the mechanism 

 of tlie lioAver. Tlu- end of the style was not so uniformly bent upward, 

 and the i.oUen-bearin.u- hairs were much more persistent. During the 

 latter period self-fertilization was effected by the lobes of the stigma 

 bending back until the papillose extremities touched the pollinated hairs. 

 The same movement may have occurred earlier in the season, but if it 

 did it was not so obvious, and many times it would have been useless, as 

 the styles were denuded of their hairy appendages, and the lobes not 

 yet reflected more than usual. 



Within the inflated limb of Prutstvimn, I'enmnnoii (L) Britten the flla- 

 ments are free, and clustered with the style under the upper lip. One 

 pair of the didynamous filaments is nearly free from the corolla tube, 

 while the other pair and the sterile fllament are imliedded in the wall 

 of the tube below the inflation. The bases of the free fllamenls are 

 dilated, with a concavity on the inner faces in which honey is secreted. 



As a result of this arrangement the throat of the corolla is so ob- 

 .trm-ted bv the two free tilaments and the style as to prevent any insect 

 from reaching the honey glands, without some special adaptation to over- 

 come the obstruction. To secure honey the visiting insects must be armed 

 with a stout pair of ."aws to force an opening between the filaments and 

 stvle and with a tongue 14 mm. long. These necessary equipments are 

 found in AHtliophora ahnn>ta Say. a small bumble-bee. For two seasons 

 this bee has been the only insect seen to enter the corolla of a large, 

 cultivated plant, under daily observation while in bloom. Anthophorte 

 never missed putting in an appearance during some part of the day. if 

 the weather was fair, and sometimes as many as half a dozen were seen 

 on the plant at the same time. 



^ntlwphom' ahrupt,r never were seen collecting p.dlen. but as they 

 forced their bodies into the inflated portion of the flower they were well 

 dusted with it on their hairy backs. This pollen was carried to the next 

 stigma under which they passed, where some of it was left, provided 

 the stigma was ready to receive it. Usually the stigmatic end of the 

 style iC pressed against the upper lip of the corolla during the first day 

 of antbesis, after that period it is bent downward and is cross-fertilized 



