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4. The Terms of Bioplastology. 
By Professor A. Hyatt, Boston, Mass., U.S.A. 
eingeg. 13. Juni 1893. 
I have written the following paper which is an abstract of one 
read before the Boston Society of Natural History, entitled »Bioplasto- 
logy and the related Branches of biologie Research«, partly in reply 
to a critical paper by Mr. Buckman and Mr. Bather and partly as 
a new contribution in the same field. 
I propose to describe in a brief way the four different lines of 
research which are usually designated by the popular terms growth, 
heredity, acquired characteristics, and the correlations of development 
of the individual (ontogeny) with the evolution of the group to which 
it belongs (phylogeny). The object being to explain the relations of 
these to each other and to give adequate reasons for the substitution 
of scientific terms for the popular names heretofore used. 
Auxology or Bathmology. 
Mr. Buckman and Bather, both well known for their original 
and instructive researches on Paleozoology in England, have recently 
in a joint paper under the title of »The Terms of Auxology«! justly 
criticised the nomenclature employed in my papers to designate the 
stages of growth and decline in the individual. ‘They have also pro- 
posed in view of the correlations which have been shown to exist bet- 
ween the transformations that occur in the stages of development and 
decline in the individual and those that characterize the evolution of 
the group to which it may belong, to designate the study of these 
correlations by the new term »Auxology« This term is open to the 
objection that it is derived from avi, meaning simply progressive 
growth up to and including the adult stages and, although in common 
with others I have felt that it has claims to be retained, there are good 
reasons why it should be restricted in application, if adopted, to re- 
searches upon growth. I have placed two terms at the head of this 
chapter partly because I have not had time to consult the proper jud- 
ges, physiologists, and obtain their decision, and partly because I am 
undecided in my own opinion. 
Cope in his » Method of Creation of Organic Forms«? used the 
therm Bathmism from Babpé<, meaning a step or threshold, to desig- 
nate growth force and it is therefore questionable whether the term 
1 Zool. Anz. No. 405. p. 406. 1892. 
2 Proc, Am. Phil. Soc. Dec. 1871 and »Origin of the Fittest«, p. VIII, ete. 
