The Tm, is of Bioplastoloyy. — Hyatt. 293 
(JkNESIOLOUY. 
The term heredity has been used in two senses, one express 
Lng the results of the action of an unknown force which guides 
the genesis of one organism from another, and a second in 
which it implies the force itself. Clearness of statement de- 
mands that some other term than heredity should be used, and 
I consequently propose to designate the study of the phenom- 
ena by the term genesiology from yivsffis, meaning that 
which is derived from birth or descent; this force itself as 
genetic force ; and the principle of heredity thus becomes 
gen ism. 
The continuity of the same element in the agamic division 
of unicellular bodies as in Protozoa makes it comparatively 
easy to explain the transmission of likeness, but this is 
growth of the ontogenic cycle. Maupas shows this clearly 
and continually speaks of the growth, full grown virility, and 
senility of his generations of unicellular, agamic protozoans. 
In fact they are obviously in a disunited form the equivalent 
of the colony of protozoans, and secondarily, although more 
remotely, the equivalent of the single metazoan, or individual, 
which is essentially a cycle of agamic cells reproducing by 
fission. 
While this likeness of agamic daughter ceils to the original 
agamic mother cell which has disappeared in them may lie 
considered a manifestation of heredity, it is also a form of 
growth and readily separable from the more complicated rela- 
tions of organisms produced by conjugation of two forms. 
When the transmission of likeness is (-.implicated with the ef- 
fects of conjugation the difficulties increase until finally in 
the bodies of tin- metazoa they culminate in a problem of 
surpassing difficulty. Heredity is as plainly written in the 
life history of the protozoan and in the growth of cells, in the 
tissues inthe budding of the metazoa and the parthenogene- 
sis, as in these more com plica ted forms, but the phenomena of 
transmission occurring after conjugation can lie separated 
from growth and considered upon entirely distinct lines. 
The theories offered show this. Thus the corpuscular the- 
ories, whet he i- gemmules or biophors or pan genes are assumed, 
assert the need of minute bodies for the transmission of char- 
acters, while on the other hand the dynamic theories, more in 
