ITS METAMOKPHY. 



171 



often elucidate the nature of organs. 1 The commonest of these 

 changes belong to what was termed by Goethe retrograde meta- 

 morphosis ; that is, to reversion from a higher to a lower form, as of 

 an organ proper to the summit or centre of the floral axis into one 

 which belongs lower down. 2 The most familiar of all such cases 

 is that of the so-called double flower, better named in Latin flos 

 plenus. In this, the essential organs, or a part of them, are 

 changed into colored flower- leaves or petals. Most flowers are 

 subject to this change under long cultivation (witness " double" 

 roses, camellias, and buttercups) , at least those with numerous 

 stamens. It occasionally 

 occurs in a state of nature. 

 The stamens diminish as 

 the supernumerary petals 

 increase in number ; and 

 the various bodies that may 

 be often observed, inter- 

 mediate between perfect 

 stamens (if any remain) and 



the outer row of petals, 



from imperfect petals, with 



a small lamina tapering into 



a slender stalk, to those 



which bear a small distorted 



lamina on one side and a 



half-formed anther on the 



other, plainly reveal the 



nature of the transformation 



that has taken place. Carried a step farther, the pistils likewise 



disappear, to be replaced by a rosette of petals, as in fully double 



1 The leading treatises are Moquin-Tandon's Te'ratologie Vegetale, Paris, 

 1841, and Masters, Vegetable Teratology, London, published for the Ray 

 Society, 1869. An earlier publication deserves particular mention, viz. the 

 thesis De Antholysi Prodromus, by Dr. George Engelmann, Frankfort on 

 the Main, 1832. 



2 To these abnormal changes, the term metamorphosis is obviously more 

 applicable ; for here what evidently should be stamens, pistils, &c., on the 

 testimony of position and the whole economy of the blossom, actually ap- 

 pear in the form of some other organ : yet even here the change is only in 

 the nisus formativus ; the organ was not first formed as a stamen, and then 

 transformed into a petal or leaf. 



FIG. 319. A flower of the common White Clover reverting to a leafy branch ; after 

 Turpin. Calyx with tube little changed, but lobes bearing leaflets. Pistil stalked; 

 the ovary open down the inner edge, and the margins of the pistil-leaf bearing leaves 

 instead of ovules. 



