July 27, 1 882 J 



NATURE 



301 



transition was not in the opposite direction? How do we 

 know that the waterlily had not petals alone to start with, 

 r.nd that these did not afterwards develop, as the Wolfian 

 hjpothesis would have us believe, into stamens? " For 

 a very simple reason. The theory of Wolf and Goethe is 

 quite incompatible with the doctrine of development, at 

 least if accepted as a historical explanation (which Wolf 

 and Goethe of course never meant it to be). Flowers can 



foot (white with yellow centre). 



and do exist without petals, which are no essential part of 

 the organism, but a mere set of attractive coloured ad- 

 vertisements for alluring insects; but no flower can pos- 

 sibly exist without stamens, which are one of the two 

 essential reproductive organs in the plant. 



Indeed, if we examine closely the waterlily petals, it is 

 really quite impossible to conceive of the transition as 

 taking place from petals to stamens, instead of from sta- 

 mens to petals. It is quite easy to understand how the 



Fig. 8.— Columbine (bluish purple). 



filament of an active stamen may become gradually flat- 

 tened, and the anthers progressively void and function- 

 less ; but it is very difficult to understand how or why a 

 petal should first begin to develop an abortive anther, 

 and then a partially effective anther, and at last a perfect 

 stamen. The one change is comprehensible and reason- 

 able, the other change is meaningless and absurd. 



In many other cases besides the waterlily, we know 



that stamens often turn into petals. Thus the numerous 

 coloured rajs of the Mesembryanthemums are acknow- 

 ledged by many botanists to be flattened stamens. In 

 Canna, where one anther-cell is abortive,, the filament of 

 the solitary stamen becomes petaloid. In the ginger 

 order, one outer whorl of stamens resembles the tubular 



Fig. 9. Fig. 10. 



Fig. 9.— Petal of columbine, secreting hnney in us spur. FlG. 10.— Monk-- 

 hood (deep blue). 



corolla, so that the perianth seems to consist of nine lobes 

 instead of six. In orchids, according to Mr. Darwin, the 

 lip consists of one petal and two petaloid stamens of the 

 outer whorl. In double roses (Fig. 2) and almost all other 

 double flowers the extra petals are produced from the sta- 

 mens of the interior. In short, stamens generally can be 



Fig. 11.— Petals of monkshood modified into nectaries. 



readily converted into petals, especially in rich and fertile 

 soils or under cultivation. The change is extremely common 

 in the families of Ranunculaceee, Papaverine/!, Matpu- 

 Kacetz, Malvacea, and Rosacea, all very simple types. 

 Looking at the question as a whole, we can see how 

 peals might easily have taken their origin from stamens, 



