146 PRINCIPLES OP PLANT-TEEATOLOGY. 



by Masters in a flower of Gypripedium Sedeni, whicli 

 contained two fertile median stamens, A^ and a^, while 

 the remaining four were all in the form of labella. 

 Here there is no increase of members, for all stamens 

 are accounted for in one way or another, and there 

 remain over no possible agencies by which the normal 

 or the abnormal labella could be formed along orthodox 

 lines. 



4. Developmental data, as Pfitzer points out, are 

 against the ordinary view. Payer, in studying the 

 flower of Galanthe, as typical of the rest of the order, 

 found that the stamens A^ and A^ of the outer whorl 

 developed quite separately from the labellum, which is 



Fia. 120. — Viola tricolor (Pansy). Pelorie flower, with all petals 

 spurred. Diagram, cp, whorl of carpels attached to stamens. 



typically organized while these two stamens can be 

 observed as distinct structures. 



Spiir-pelury. — Hemsley describes this feature in the 

 lateral petals of all the flowers of an inflorescence of 

 the butterfly- orchis {Plafauthera cMorantha) : a very 

 rare case. 



In other cases that half of each lateral petal which 

 is nearest the labellum becomes labelliform, the other 

 half being unchanged. 



Mr. Weathers sent a sketch he made of Angraecum 

 sesqtdpedale with a spurred lateral petal, a unique case 

 for this genus.* 



In the pansy {Viola tricolor), besides the normally- 



* Recorded in ' Proceedings of Scientific Committee R. Hort. Soc./ 23rd 

 April, 1892. 



