296 The American Geologist. November, 1898 
game subj eel more extensively in his "Nattirlichen Existenz- 
bedingungen der Thiere." * 
The use of the term entergogenesis makes it practicable to 
indicate the essential distinction existing between the modifi- 
cations produced through the mediation of internal forces 
;m<l those arising as the direct results <>l' the action of ex- 
ternal forces by means of the term ectergogenesis and ecter- 
gogenic. 
These explanatory remarks serve t<> show thai ctetology is 
a branch of research which needs to be isolated from re- 
searches upon growth and genesiology, since it is devoted to 
the study of the origin of acquired characteristics and there- 
fore necessarily considers all of the internal reactions of the 
organisms in response to the action of physical forces, as 
well as the more obscure reactions of structures which are 
produced solely by (or supposed to be produced by) the direct 
physical or chemical action of external physical forces. 
BlOPLASTOLOGY. 
The separation of auxology (or bathniology), genesiology, 
and ctetology, shows also that the study of the correlations of 
ontogeny and phylogeny is distinct from either of these; 
and this branch of research can be designated by the term 
bioplastology from Bios, life, and nXaGTog meaning moulded 
or formed. f 
To sum up in a lew words the rather ambitious aims of this 
^Translation by Minot, MacMillan, 1892. 
|Bioplasm, bioplast, bioplastic have already been used by Beale 
and others for the living cell and its contents, but the term "bioplasto- 
logy"' has not been used nor have the names proposed by Beale been 
generally adopted. If they were, bioplasmology would cover the re- 
quirements of students of such phenomena: and there is already in 
use plasmology with about the same meaning, and histology for the 
descriptive side of the study of cellular structures. 
Biogeny has been used in extra-scientific literature by Fiske with the 
same meaning as Bioplastology.and Haeckel has named the law of em- 
bryonic and ancestral correlation the law of biogenesis, but there is 
a strong objection to both of these. Biogenesis is the name given to 
the theory of the origin or genesis of life from life in contradistinction 
to the assumption of spontaneous generation, or abiogenesis, and has a 
well established place in scientific literature. Therefore while the law 
of correlation of the stages of development and those of the evolution 
of the phylum, may, if one chooses, be called a law of biogenesis, it is 
more accurate to consider it a laic of correlation in bioplastologu or 
better still the law of palingenesis or regular repetition of ancestral 
characters, which exactly expresses what the discover Louis Agassiz 
saw and described. 
