16 MORPHOLOGICAL DEVELOPMENT. 



of elongation in various types; and that in each kingdom 

 acquisition of the common trait has had a tendency now to 

 obscure morphological equivalence, and now to give the ap 

 pearance of kinship where there is none. A further pur 

 pose has been to prepare the way for a question hereafter 

 to be discussed whether, in the various types of either king 

 dom, the elongation is effected in the same ways or in dif 

 ferent ways. We shall have to ask whether the vertically 

 growing part is always, like that of Lessonia, a simple in 

 dividual, or whether, as possibly in Phaenogams, it is a united 

 series of individuals; and similarly whether the elongated 

 body is always single, like that of a mollusc, or whether, as 

 possibly in annulose animals, it is a series of united in 

 dividuals.] 



