DIALYSIS. 69 



the same as that of the affected organ, but there are 

 other examples, probably equally due to fissiparous 

 division, where the new growth is either parallel to, or 

 even at angle with the primary organ. Of such nature 

 are some of those instances wherein two leaves appear 

 to be placed back to back. These partake of the nature 

 of excrescences or of exaggerated developments, and 

 hence will be more fully treated of under the head of 

 hypertrophy. It must be remembered that in some of 

 these cases the fission may be a resumption of charac- 

 ters proper to the species under natural conditions, 

 but lost by cultivation or otherwise. Thus, Mr. Buck- 

 man accounts for " finger-and-toe" in root-crops on 

 the principle of reversion to the wild form. 



CHAPTER II. 



DIALYSIS. 



This term is here made use of in the same sense as 

 in descriptive botany, to indicate the isolation of parts 

 of the same whorl ; it is thus the opposite of cohesion. 

 Morren, as has been previously stated, employed the 

 word in a different sense, while Moquin-Tandon' in- 

 cluded cases of this description under the category of 

 " Disjonctions qui isolent les organes." 



Dialysis, as here understood, may be the result of 

 an arrest of development, in consequence of which 

 parts that under ordinary circumstances would become 

 fiised, do not do so ; or, on the other hand, it may be 

 the result of an actual separation between parts primi- 

 tively undivided. As it is not possible in every case to 

 distinguish between the effects of these two diverse 

 causes, no attempt is here made to do so. 



Loc. cit., p. 208. 



