Hyatt.] 
114 [A,. 
a full knowledge of this, the inorpliology of the group cannot l)e 
properly translated, nor can the forms be taxononiically treated 
with reference to their natural relations. This branch of research 
aims to complete Von l>aer's law and Louis Agassiz's great dis- 
covery of the correlations of palingenesis and phylogenesis, and 
it, therefore, asserts an equal utility for the metamorphoses of 
the nepionic, neanic, ephebic, and gerontic stages, provided 
these be applied in each group according to tlie ontogenetic 
development of the cycle in the zoon and its phylogenetic evolu- 
tion in the same group. 
Stages of Mokphogenesis. 
As remarked by Buckman and Bather, "it is possible to trace 
the evolution of one character from its first appearance to its final 
loss, right through the history of a long line of individuals." 
They also say, "the various characters that go to the formation 
of an individual or a race, at any period of its development, may 
themselves differ greatly from one another in the degree of their 
own development." And further, "for the designation of the 
successive stages in the history of a character, the ontogenic 
terms might be used with the addition of the prefix morpho — e. y. 
jnorphobrephic [here nepionic], morplie])hebic." These sugges- 
tions are certainly useful, but they appear to me to cover both 
ontogeny and phylogeny, while according to the title used by 
these gentlemen, " Stages of individual morphogenesis," the}' were 
meant to apply only to ontogeny. 
If one traces the history of any one character, something which 
every student of bioplastology must habitually do in actual j)iac- 
tice, throughout a chain of individuals whether these are members 
of one variety or one species, or whether they lead into distinct 
species, as they are a])t to do, he is studying the ])hylogeny of 
that characteristic. It would seem therefore that the ])refix 
"phyl" would be applicable in such cases, whereas the use of a 
single term foi- Ixith the phylum and the individual, i-spccially 
tlie prefix "niorpiio," would be likely to confuse. 
It follows from the principles of bioplastologytli.it no consider- 
ation is here given to transient characters or those having no 
genetic meaning. It is, however, (piite i)ossible, although I have 
no exi)erieJiee ti> rail up to illustrate this statement, that charac- 
