330 
by the increase in numbers of forms etc., or the cycle of the ontogeny 
as shown by the increasing complexity of the development and its 
decline, the anaplasis, metaplasis and paraplasis of the individual, or 
one may describe the cycle as exhibited by the embryonic, nepionie, 
neanic, ephebic and gerontic stages, or the cycle of the phylogeny as 
exhibited by the corresponding stages of evolution designated by their 
appropriate prefix »phyl«. 
There appears to be real need of two terms under the head of 
cycle, one for ontogeny and the other for phylogeny. It is proposed 
to use in this way ontocycle or ontocyclon for the ontogeny, meaning 
the cycle of the individual, and phylocycle or phylocyclon for that of 
the phylum. This will make it practicable to use the terms mono- 
cyclon or monocyclic, polycyclon or polycyclic etc. to describe the 
number of cycles observed. Thus the Ammonoids are polycyclic, the 
Arietidae are decacyclic, the genus Coroniceras is an incomplete mo- 
nocycle. 
It is not necessary to defend these terms before students of Bio- 
plastology, they will be tested and if convenient adopted. For the be- 
nefit of others it may be mentioned that the cycle is of all degrees of 
development in ontogeny. Thus insecta are apt to stop at the ephebie 
period and in many other animals there is a similar limitation. 
_. Those who try to find a complete cycle of metamorphoses in their 
own special lines of research will be often disappointed and probably 
question that it exists at all. Thus for several years I could not find 
any evidence of its existence among certain Cephalopods, those having 
a primitive organization like Endoceras and Orthoceras, but I have 
since seen well marked senile stages in these shells. 
Stages of Morphogenesis. 
As remarked by Buckman and Bather »it is possible to trace 
the evolution of one character from its first appearence 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 charac- 
ter, the ontogenic terms might be used with the addition of the prefix 
morpho- e. g. morpho-brephic (here nepionic) »morphephebic«. These 
suggestions are 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« they were meant to apply Bi 
to Ontogeny. 
