li'.M The American Geologist. November, ia»s 
accord with physical phenomena, assume thai there is a trans- 
mission of molecular energy through growth. Some of these 
views support Hering's theory of what may be called mneme- 
genesis, namely, that heredity i- a form of unconscious or- 
ganic memory, and this from my point of view is the only sat- 
isfactory one yet brought forward. 
Heredity is obviously manifested for the most part in the 
developmental results of growth and appears chiefly in the 
cytoplasmic structures which Dr. Minot so clearly places be- 
fore us as constantly increasing with age, while the compara- 
tive size of the nucleus which represents the power of growth 
force decrease-. Whether this be granted or not.it can hardly he 
denied, that, in describing the development of organisms along 
ontogenetic and their evolution along phylogenetic lines, we 
are dealing with cycles of progression and retrogression which 
are quite distinct from the growth of the body as determined 
by the laws that govern its increase and reduction in bulk, and 
that one cannot describe the study of both series of phenom- 
ena under the same general term without danger of confusion. 
Genism, in brief, is the transmission of likeness from one 
ontogenic cycle to another of the same species. It appears t<> 
be due to the same factors as the perpetuation and rejuvenes- 
cence of the cycles themselves, namely, the union of two 
forms of distinct ontogenic c} T cles of the same species or kind. 
( Itetology.* 
Weismann and his supporters deny that ctetetic or acquired 
characters are inheritable, but it is safe to make the assertion 
that this will not be maintained by the students of bioplastol- 
ogy. Within the limits of my own experience in placing tin- 
genetic relations of varieties and species of fossil cephalo- 
pods and other groups through geologic time, although I have 
tried to analyze the behavior of all kinds of characteristics. 
I have failed to find any such distinctions. If Weisniann's 
theory is true it ought to be practicable to isolate in each type 
some class or classes of modifications that would be distin- 
guishable by the fact that they were not inherited. 
The only known cause of modification as demonstrated by 
the suitability of variations in existing characteristics, and 
"'■'•' A Ti)T(>>, something acquired. 
