CHAP. VII. SIZE OF THE COROLLA. 307 



female form ; in one of the latter plants the stamens were 

 so tall that the anthers embraced the style as in the herma- 

 phrodites, but they contained only a few grains of pollen, 

 and these in an aborted condition; in another female, on 

 the other hand, the anthers were much more reduced in 

 size than is usual. Lastly, Dr. Dickie has shown that with 

 Eriophorum angustifolium (Cyperaceae) hermaphrodite 

 and female forms exist in Scotland and the Arctic regions 

 both of which yield seed.* 



It is a curious fact that in all the foregoing po- 

 lygamous, dioacious, and gyno-dioecious plants in which 

 any difference has been observed in the size of the 

 corolla in the two or three forms, it is rather larger in 

 the females, which have their stamens more or less or 

 quite rudimentary, than in the hermaphrodites or males. 

 This holds good with Euonymus, Rhamnus catharticus, 

 Ilex, Fragaria, all or at least most of the before-named 

 Labiatse, Scdbiosa atro-purpurea, and Echium vulgare. 

 So it is, according to Von Mohl, with Cardamine 

 amara, Geranium sylvaticum, Myosotis, and Salvia. 

 On the other hand, as Von Mohl remarks, when a 

 plant produces hermaphrodite flowers and others 

 which are males owing to the more or less complete 

 abortion of the female organs, the corollas of the 

 males are not at all increased in size, or only excep- 

 tionally and in a slight degree, as in Acer.f It seems 

 therefore probable that the decreased size of the female 

 corollas in the foregoing cases is due to a tendency to 

 abortion spreading from the stamens to the petals. We 

 see how intimately these organs are related in double 

 flowers, in which the stamens are readily converted 

 into petals. Indeed some botanists believe that petals 

 do not consist of leaves directly metamorphosed, but of 



*Sir J. E. Smith, 'Transac- of the Lirnisean Society of Botany,' 

 tionsof the Linnsean Society,' vol. vol. ix. 1865. p. 161. 

 xiii. p. 599. Dr. Dickie, 'Journal f ' Bot. Zeitung,' 1863, p. 326. 



