194 PRINCIPLES OF GARDENING. [CH. VI. 



shorter, and as the flower always holds itself erect, 

 the pollen cannot reach the stigmas, but would fall 

 to the bottom of the corolla, if it were not for the 

 agency of a particular insect. This diminutive vi- 

 sitant is the T'qmla pennicornis, which entering the 

 tube in search of honey, in vain tries to repass the 

 phalanx of hairs which easily yielded to it an en- 

 trance ; in its search for a way of escape, it carries 

 the pollen to the stigma, and impregnation being ef- 

 fected, the hairs lose their rigidity, sink to the side 

 of the tube, and the prisoner easily escapes. 



The efficient agency of insects suggested that in 

 hot-houses from whence they are almost totally 

 excluded, other artificial means might be adopted 

 with success to render fertile flowers that had 

 hitherto failed in producing seed. One of the 

 earliest instances on record of the experiment being 

 tried with a prosperous result was on the Abroma 

 augusta, which had bloomed unfertilely for several 

 years in a hot-house at Berlin. The gardener by 

 the aid of a hair pencil applied a little pollen to the 

 stigma, and for the first time perfect seed was pro- 

 duced, from which plants were raised. This practice 

 is now very generally adopted to all plants cultivated 

 under glass from which a produce of either fruit or 

 seed is desired ; for fruit rarely attains its full size if 

 the seeds within it are unfertilized. Thus the gar- 

 dener always finds the advantage of using the camel 



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