STRUCTURE.] DEDUPLICATIOK 331 



found to be mutually so arranged, that if the internode which 

 separates them were removed, the leaves would exactly alter- 

 nate with each other ; and as there are no known exceptions 

 to this law in real leaves, it is natural that it should not be 

 departed from in any modifications of them. 



Nevertheless, M. Dunal has imagined that when two organs 

 are opposite each other in the same flower, they exhibit a case 

 of what he calls unlining (dedoublement, or deduplication) , 

 assuming that in certain cases there is a tendency on the 

 part of an organ to divide or separate into two or more layers, 

 each having the same structure. 



The manner in which M. Dunal and his followers speak 

 of this imaginary quality is as follows : 



" De Candolle has observed, in his Organographie Vegetale, 

 that the multiplication of the organs of a flower belongs to 

 two different systems: 1st, the iucrease of the number of 

 whorls by other whorls similar to one of them ; 2nd, by the 

 increase of the number of pieces of one and the same whorl 

 by the occasional development of organs similar to those of 

 which the whorl is composed. The multiplications or un- 

 linings which I have mentioned, belong to the last system, 

 with this difference, that in the cases I have noticed they are 

 not occasional or accidental, but habitual. I said, when 

 speaking about them, ( All organs of plants, originally united, 

 separate in different ways, in different proportions, and then 

 appear under different aspects. They all pass out of each other 

 (desemboitent] ; they all unline ; but they sometimes separate 

 even when they are generally united in the plane of their 

 general symmetry ; or, which is the same thing, we find many 



organs where we ought to find but one single one 



When, for example, we find several stamens instead of one 

 normal one, I say that they are produced by the unlining or 

 multiplication of the primitive stamen, &c. 



" This phenomenon being well understood, let us examine 

 the expressions employed to signify it. That of multiplica- 

 tion is tolerably correct, but very vague. The term unlining 

 is more precise ; it is a better explanation of the fact, as I 

 understand it ; that is to say, a separation of parts originally 

 closely united, since they spring from one single fibre. This 



