430 BOTANICAL GAZETTE | JUNE 
other words, since all parts of the plant actually are organs (that is 
have some meaning in the life of the plant), new organs can arise 
only by the transformation of previously existing ones. We face here a 
sharp contrast in the two systems of morphology. ‘The idealistic sys- 
tem, laying as it does great stress upon members in distinction from 
organs, comes to regard these members as if they had a real existence, 
forgetting that the conception of the member is a pure abstraction of 
the mind, a sort of mental composite photograph, with no objective 
equivalent, and that members apart from organs do not really exist. 
The conception of the member as an entity having once been formed, 
metamorphosis is naturally regarded as the differentiation of an organ 
out of a member, and this not only phylogenetically but also onto- 
genetically; so that by those who carry the idealistic system into 
ontogeny at all, the ontogenetic unfolding of any organ is viewed asa 
differentiation from primordia (Anlagen) which, after the analogy of 
the members, are supposed to be indifferent in their nature. Not only, 
however, is this view untenable upon philosophical grounds, but it is 
negatived by the fact that in cases where metamorphoses are experi-_ 
mentally brought about, embryology shows that the process is actually 
one of transformation of one function-structure into another, and not 
of differentiation of a function-structure out of a neutral or indifferent 
primordiui (Anlage). But this subject is so clearly treated by Goebel _ 
in the Introduction to his Organography that it needs no further con- 
sideration here. How these, in their origin purely ontogenetic, meta- 
morphoses become fixed in the phylogeny, is an entirely separate 
question, the solution’ or non-solution of which does not in the least 
affect the truth or non-truth of this principle. The idealistic concep: 
tion, that an organ is formed by differentiation from a member, 
implies as a corollary that each organ is but one step, so to speak, 
from a member, and should be readily reducible to it; hence arise the 
attempts to explain all parts of such complex and specialized structures 
as epigynous flowers in terms of leaf and stem, necessitating the 
adnate calyx theory with its requirement of extraordinary assumptions 
as to growing together of parts, etc., entirely unsupported by the facts 
of development. 
SEVENTH, the principle of gradation in morphological membership, 
involving the existence of degrees of morphological independence, 
culminating in the attainment of full morphological membership with 
full independence. Or, it may be expressed thus: in the progressive 


