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R . Ruggles Gates. 
as recapitulation, adaptation, inheritance, and distribution. The 
first class of characters are (as already expressed in Chapter II.) 
cell-characters, which have arisen through mutations, are repre¬ 
sented in every cell of the organism, and are usually inherited as 
distinct units. Since they arise in and are carried by the nuclei 
they may be called karyogenetic. To the second category 
belong characters which arise gradually in the organism through 
impact of the environment or through “ orthogenesis,” 1 may apply 
only to localized portions in the life-cycle of the organism, and at 
first are not incorporated in the germplasm. Such characters we 
may call organismal 2 , in contradistinction to cell-characters. 
Organismal characters may imply an increase in the length of the 
life-cycle, as strikingly evidenced in so many animal larvae which 
undergo metamorphosis, or they may show stages in shortening, as 
in the gametophytes of many higher plants. 
The attitude of experimental biologists to the questions of 
recapitulation and inheritance of acquired characters (although the 
former has never fallen into the same disrepute as the latter) has 
been generally one of skepticism and denial. Reasons for adopting 
a different position may be given as follows: (1) the difficulty of 
explaining adequately the abundant facts of recapitulation in plants 
and animals by means of mutations or changes originally germinal; 
(2) the logical necessity of the principle of functional inheritance in 
some form to explain the origin of embryonic recapitulatory 
characters involving adaptation; (3) the approach to an under¬ 
standing, through such agencies as hormones and enzymes, of how 
the transmission and ultimate germinal fixation of somatic modifi¬ 
cations may take place; (4) the slowly accumulating direct 
experimental evidence for parallel induction and the transmission 
of modifications. 
In contrasting organismal with cell characters we are con¬ 
trasting two points of view regarding the organism which are at 
least as old as Aristotle and Empedocles. Modern representatives 
of these views speak of the organism as a whole on the one hand, 
and of elementalist or particulate theories on the other. It scarcely 
needs pointing out that elementalist conceptions, particularly of 
1 An orthogenetic result may also of course arise from a succession of 
germinal changes or mutations following each other in any line of phylogeny. 
* In the Linnean discussion, Professor F. E. Weiss suggested the obvious 
antonym cytogenetic for this category of characters, since they are apparently 
cytoplasmic in origin. This term had already been considered, but was finally 
discarded because “organismal ” expressed better the idea desired. Never 
theless it will be a useful term in certain connections. 
