290 



METAMORPHV. 



tions being petaloid and continuous with the dilated 

 filament. Not unfrequently these semi-petal oid sta- 



^1^ 



^^^ 



Fig. 155. Four-winged fQaments of Bhododendron. 



mens adhere to tlie fronts of the petals, and then it 

 appears, at a first glance, as if three organs were stuck 

 together, one in fi'ont of another, while in reahty there 

 are but two.^ (See ante, p. 35, fig. 12.) 



The change in the anther, above alluded to, must not 

 be mistaken for that far more common one in which 

 only a small portion of the anther becomes petaloid, 

 forming a sort of lateral wing or appendage to the 

 poUiniferous portion, as happens normally in Pterandra, 

 and is common in some double fuchsias. In this 

 latter instance there is but a single wing, and the 

 nature of the case is obvious. 



Double flowers of OrchidacecB generally arise from 

 petalification of the filaments, with or without other 

 coincident changes. What makes double flowers in 

 this order the more interesting is the development, in 

 a petaloid condition, of some or all of those stamens 

 which under ordinary circumstances are wholly sup- 

 pressed, so that the morphological structure of the 

 flower, at first a matter of theory, becomes actually 



' Mastere, " On Double Flowers," * Rep. Intemat. Bot. Congress,' 

 London, 1866, p. 127. 



