The Terms of Bioplastology. — Hyatt. 291 
have recently in a joint paper under the title of "The Terms 
of Auxology"* justly criticised the nomenclature employed in 
my paper to designate the stages of growth and decline in 
the individual. They have also proposed in view of the cor- 
relations which have been shown to exist between the trans- 
formations that occur in the stages of development and de- 
cline in the individual and those that characterize the evolu- 
tion of the group to which it may belong, to designate the 
study of these correlations b} T the new term "auxology." 
This term is open to the objection that it is derived from 
otvBif, meaning simply progressive growth up to and includ- 
ing 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 researches upon growth. I have placed two terms at the 
head of this chapter partly because I have not had time to 
consult the proper judges, physiologists, and obtain their de- 
cision, and partly because I am undecided in my own opinion. 
Cope in his ''Method of Creation of Organic Forms"f used 
the term Bathmism from B(rVj.iog, meaning a step or 
threshold, to designate growth force, and it is therefore ques- 
tionable whether the term Bathmology should not be substi- 
tuted for Auxology in order to give uniformity to the nomen- 
clature. 
It is not necessary to discuss this here and the facts are 
merely mentioned to call attention to this question ami bring 
out expressions of opinion. 
Dr. C. S. Minot, who has given the first demonstration of 
the fundamental law of growth* has shown that the common 
notions with regard to the action of this force in organisms 
are erroneous. His plotted curves of the actual additions in 
hulk of the body by growth during equal intervals of time in 
guinea pigs show that these increments are in steadily de- 
creasing ratio to the increase of weight of the animal from a 
very early age. He was so much impressed by these facts 
*Zool. Anz. No. 405. p. 406. 1892. Republished in the American 
Geologist, vol. xn, p. 4:>. 
tProc. Am. Phil. Soc, Dec, 1871, and "Origin of the Fittest," p. viii. 
etc. 
^''Senescence and Rejuvenation." Journ. Phys.. xii. No. 2, 1891, 
and address on "Cert. Phen. of growing old," Am. Assoc. Adv. of Sci., 
xxxix. Aug., 1890. 
