come more complex
and differentiate into a greater number of parts, because each group of
micellae of the idioplasm produces its specific effect with regard to
inner structure, outer form, and function.

7. DETERMINANTS: THEIR ORIGIN AND DISAPPEARANCE.

Since a particular cluster or group of micellae of the idioplasm produces
a particular phenomenon in the organism, the former is designated as the
determinant (_Anlage_, see p. 49) of the latter. Thus the organism must
contain at least as many determinants in its idioplasm as there are
different phenomena in its inheritable ontogeny; and if new phenomena
appear in it, new clusters of micellae must previously have been
introduced into the idioplasm, or the orientation and arrangement of
clusters already present must have been changed. The formation of such a
determinant, whether it concerns the perfecting of the organism or its
adaptation to environment, always proceeds very slowly, and as a rule
has no effect before its completion. Hence along with perfected
determinants the idioplasm always contains growing and incomplete
determinants.

If a phylogenetic line comes under the influence of other external
conditions and other external stimuli than those which have hitherto
acted upon it, a new and corresponding arrangement of the micellae
appears phylogenetically in the idioplasm. At the same time the other
adaptation determinants remain either undisturbed, or the new
determinant is formed at the expense of related determinants which are
already present and which may at last entirely vanish. Hence along with
growing and complete determinants the idioplasm always contains likewise
weakened and vanishing determinants. From the fact that a phylogenetic
race is thrown repeatedly among different external conditions, it may at
last unite in its idioplasm a large number of developing, mature, and
vanishing adaptation determinants. This number is noticeably increased
if in consequence of interbreeding a fusion of related idioplasms take
place.

8. DEFINITE NOTIONS WITH REGARD TO THE MORPHOLOGY OF THE IDIOPLASM.

Since in the phylogenetic development of the plasma the thicker
idioplasm is differentiated from the more fluid soma-plasm (Sec. 5), the
former has the tendency by nature to assume a reticular arrangement. The
strands of this network consist, in conformity with their origin, of
parallel rows of micellae extending lengthwise. These rows of micellae
are combined in