458 DE. M. T. MASTERS ON THE SUPERPOSED 



the buds be examined, or if the petals be carefully stripped off, it 

 may be seen that the petals, instead of being arranged in a spiral 

 manner, increasing in size from below or beneath upward, are dis- 

 posed in cycles or whorls, each cycle consisting of three petals. 

 The cycle is probably in this case merely a spiral depressed or 

 undeveloped, owing to the arrest of development of the internodes 

 between successive petals. The members of one cycle alternate 

 in position with those of the next ; and so it comes about that the 

 pieces of the third whorl are placed immediately over those of the 

 first, the members of the fourth over those of the second, and so on. 

 The peculiar star-like form and the apparent superposition are there- 

 fore due to the substitution of a verticillate or cyclic for a spiral ar- 

 rangement and to the alternation of parts of successive whorls. 

 The thalamus of the ordinary Camellia flower is largely developed, 

 thick and conical, or more or less dome-shaped ; and, on a transverse 

 section, the vascular bundles are seen to form a continuous or 

 more or less broken ring surrounding a central medulla of stel- 

 liform cells. The thalamus of the star-like Camellia is more dis- 

 tinctly 6-sided than in the ordinary form, the sides being some- 

 what concave ; and on transverse section the vascular bundles, 

 especially near the upper extremity, may be seen to be arranged 



groups 



When 



theory of chorisis was enunciated by Dunal, it met with great 

 opposition, and, in this country, especially from Lindley. One of 

 the arguments used by this eminent botanist in his ' Elements of 

 Botany * (1847), p. 76, figs. 157, 1 58, was derived from the star-like 

 Camellia to which allusion has just been made. Lindley assumed 

 that the advocates of the theory of chorisis would consider 

 this Camellia an illustration of their views. Erom the ap- 

 pearances presented on a superficial examination, it would not 

 be unnatural to suppose that an upper petal placed apparently 

 directly over a lower one was derived from the latter by the 

 process of chorisis. Against such a supposition, Lindley argued 

 that it was unreasonable to suppose that on one and the same 

 individual plant the arrangement of the parts of different flowers 

 should be different. It seemed to him contrary to nature that two 

 diverse plans of floral construction should be followed in the same 

 plant ; and he therefore expressed his opinion that the example 

 afforded by this Camellia " seems conclusive against reduplication 

 having any existence in nature.' ' No doubt Lindley was right 

 in denying the existence of chorisis in this particular instance, 



