CHif. VI. ANGR^CUM SESQUIPEDALE. 1G5 



the stigma so well as I did in withdrawing them. Aa 

 the margins of the cleft rostellum must be uptui-ned 

 before the discs adhere to a cylindrical body, during 

 its withdrawal, the pollen-masses become affixed some 

 little way from its base. The two discs did not always 

 adhere at exactly opposite points. Now, when a moth 

 with the poUinia adhering to the base of its proboscis, 

 inserts it for a second time into the nectary, and exerts 

 all its force so as to push down the rostellum as far as 

 possible, the pollen-masses will generally rest on and 

 adhere to the narrow, ledge-like stigma which projects 

 beneath the rostellum. By acting in this manner with 

 the poUinia attached to a cylindrical object, the pollen- 

 masses were twice torn off and left glued to the stig- 

 matic surface. 



If the Angrsecum in its native forests secretes more 

 nectar than did the vigorous plants sent me by Mr. 

 Bateman, so that the nectary ever becomes filled, small 

 moths might obtain their share, but they would not 

 benefit the plant. The poUinia would not be with- 

 drawn until some huge moth, with a wonderfully long 

 proboscis, tried to drain the last drop.* If such great 

 moths were to become extinct in Madagascar, assur- 

 edly the Angraecum would become extinct. On the 

 other hand, as the nectar, at least in the lower part 

 of the nectary, is stored safe from the depredation of 

 other insects, the extinction of the Angrsecum would 

 probably be a serious loss to these moths. We can 

 thus understand how the astonishing length of the 



* Mr. Belt aiiggesta (' The Na- ment can thus be accounted for. 



turalist in Nicaragua,' 1874, p. I have no doubt of the truth of 



133) that the great length of the this principle, but it is hardly 



nectary of this plant serves to applicable here, as the moth has 



prevent other moths which are to be compelled to drive Its pro- 



not well-adapted for the fertiliaa- boscis as deeply down as possible 



tinn of the flowers from sucking into the flower, 

 the nectar, and that its develop- 



