383 ON CHORISIS. 



and always in idea could none of them exist as living parta without 

 4he others, they are different portions of one organized substance, and 

 the consideration of the sense in which they are different, only the 

 more impresses us with the impossibility of supposing such elements 

 as would ordinarily produce one leaf, capable of producing, under any 

 stimulus, many leaves standing in parallel planes, each containing all 

 the parts of the one. But it may, perhaps, be thought that there is 

 some other mode of representing this matter not liable to the preliml- 

 jftary objection here offered. Dr. Gray, who probably presents the 

 subject as judiciously and plausibly as any one has done, and whose 

 authority would justly go as far as mere authority ever can, is disposed 

 to treat the question as one of fact, as if he said : it cannot be denied 

 that examples occur of multiplication of organs opposite to one another 

 in the flower which do not admit of explanation by their belonging to 

 successive circles — these facts claim consideration whether we caa 

 explain them or not, but when stated, an explanation may be attempt- 

 ed — accordingly he begins by putting aside the theory to which ray 

 remarks above directly apply, in the words : " The name dedouble- 

 ment of Duval, which has been translated deduplication, literally 

 means unlining ; the original hypothesis being, that the organs in 

 question unline, or tend to separate into two or more layers, each hav- 

 ing the same structure. "We may employ the word deduplication, ia 

 the sense of the doubling or multiplication of the number of parts, 

 without receiving this gratuitous hypothesis aS to the nature of the 

 process, which at best can well apply only to some special cases. The 

 word chorisis, also proposed by Duval, does not involve any such 

 assumption, and is accordingly to be preferred." He adds, respect- 

 ing transverse chorisis : " Some examples may be adduced before we 

 essay to explain them." I am myself disposed, nevertheless, to en- 

 deavour to understand and consider the theory proposed, and then try 

 its application to the facts. These facts are certain phenonena in 

 flowers which are, if possible, to be brouglit under general laws of 

 structure. Is it certain that laws previously known do not apply to 

 them ? and if this must be admitted is the hypothesis called transverse 

 chorisis the only possible one, and does it ansv^er fully the require- 

 ments of the case ? These questions we can only answer when we 

 know what the hypothesis is — what supposition respecting the origin 

 of the parts is adopted. That of Duval is quite intelligible, and in the 

 case of collateral chorisis seems reasonable, applying well to some of 



