DEGENERACY OF FLOWERS. 281 



extine and intine, their development is arrested and, while 

 still in contact, a common extine clothes the whole of each 

 massula. Moreover, it is only after the pollen mass has 

 been placed upon the stigma that the development is con- 

 tinued.* With regard to the pistil the first sign of degeneracy 

 is seen in the parietal placentation which prevails, and more 

 especially in the rudimentary character of the ovules, every 

 part of which is degraded. Even after fertilisation the 

 embryo cannot grow to maturity, but remains in the arrested 

 pro-embryonic condition. Having no albumen or nucellus- 

 tissue wherewith to nourish the embryo, the suspensor does 

 its best by elongating and escaping from the micropyle, and 

 then, fastening itself like a parasite upon the placentas, ex- 

 tracts nourishment therefrom — the result being that myriads 

 of seeds never succeed (at least in cultivation) in developing 

 even the pro-embryo ; and one can only infer that such is 

 the case in nature. f 



In the cultivation of other flowers analogous phenomena 

 are met with. The more highly cultivated a florists' flower 

 may be, the less good seed is procurable ; while the poorer 

 ones — that is, from a florist's point of view — or "weedy" 

 looking plants furnish plenty, and are highly prolific. 



The rationale of these facts, whether taken from nature 

 or from cultivation, I believe to be fundamentally the same, 

 viz. the adaptation to insect agency and the result of repeated 

 intercrossing, which enhances the development and form of 

 the perianth especially, and generally of the stamens as well. 

 At least the kinds of energy which are concerned in the 

 manufacture of these whorls are more especially forced into 

 activity by the stimulus received from without. On the 

 other hand, the pistil suffers proportionately in all its parts 



* Mr. B. T. Lowne, Orchid Conference, etc., I.e., p. 48. 



t M. Guignard has drawu similar couclusions. See above, p. 172. 



