ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
727 
Bioplastology.* — Prof. A. Hyatt, partly in answer to the criticisms 
of Messrs. Buckman and Batherj[| describes the four different lines of 
research which are usually designated by the terms, growth, heredity, 
acquired characteristics, and the correlations of ontogeny with phytogeny. 
While acknowledging the justice of Messrs. Buckman and Bather’s 
criticisms of his nomenclature, Prof. Hyatt suggests that Bathmology 
is a term preferable to Auxology, and points out that the term growth 
covers decrease in bulk due to development and use, as well as increase. 
When one passes beyond this one sees that the manifestation of growth- 
energy arises from two facts — a living organism and the assimilation of 
nutritive matter. 
As the term heredity has been used in two senses — that is as expressing 
the results of the action of an unknown force which guides the genesis of 
one organism from another, and also as implying the force itself — it is 
well to have new terms. The study of the phenomenon may be called 
Genesiology, the free genetic force and the principle of heredity Genism. 
Genism is the transmission of likeness from one ontogenic cycle to 
another of the same species, and appears to be due to the union of two 
forms of distinct ontogenic cycles of the same species. 
The term Ctetology is the term proposed for the study of acquired 
characters, and the modifications produced through the mediation of 
internal forces are to be said to be due to entergogenesis, and those due 
to external forces to ectergogenesis. The separation of Auxology (or 
Bathmology), Genesiology, and Ctetology shows that the study of the 
correlations of ontogeny and phylogeny are distinct from these ; that 
branch of research may be designated by the term Bioplastology. 
In Ontogeny the following terms are suggested : — 
Structural 
Conditions. 
Stages. 
(Embryonic 
Stages. 
Embryonic 
Anaplasia 
(Haeckel) 
Larval or young .. 
Nepionic . 
Immature or adolescent 
Neanic 
(Haeckel) } 
Mature or adult 
Ephebic . 
Paraplasis . . 
Senile or old 
Gerontic . 
Substages. 
Several (no popular names). 
I Ananepionic. 
Metanepionic. 
Paranepionic. 
{Ananeanic. 
Metaneanic. 
Paraneanic. 
i Anephebic. 
Metephebic. 
Parephebic. 
Anagerontic. 
Metagerontic. 
Paragerontic. 
In the comparison of ontogenetic and phylogenetic stages the 
following terminology may be used : — 
Ontogeny. 
Structural 
Conditions. 
Stages. 
{Embryonic 
Nepionic 
Neanic 
Metaplasia . . Ephebic 
Paraplasis .. Gerontic 
Phytogeny. 
Structural Conditions. Stages. 
Ij Phylembryonic. 
Phylanaplasis < Phylonepionic 
| Phyloneanic. 
. . Pbylometapla8is . . Phylephebic 
. . Phyloparaplasis . . Phylogerontic 
Dynamical. 
Epacme. 
Acme. 
Paracme. 
* Zool. Anzeig., xvi. (1893) pp. 317-23 ; 325-31. 
f See tliis Journal, supra, p. 157. 
