nr 
319 
When one passes beyond this and attempts to deal with the 
characteristics of ontogeny or phylogeny he at once finds himself in 
“the presence of other forces, such as heredity and other processes 
namely, the acquisition of new characters and the renewal of the 
powers of growth in nuclear substances by means of conjugation. 
The manifestation of growth energy in brief arises from two fac- 
tors, or at any rate, is always found associated with two, a living orga- 
nism and assimilation of nutritive matter, and is an obvious result of 
their union. 
Genesiology. 
The term heredity has been used in two senses, one expressing 
the results of the action of an unknown force which guides the gene- 
sis of one organism from another and a second in which it implies the 
force itself. Clearness of statement demands that some other term 
than heredity should be used and I consequently proposed to designate 
the study of the phenomena by the term Genesiology from [évectc, 
meaning that which is derived from birth or descent, this force itself 
as genetic force, and the principle of heredity thus becomes genism. 
The continuity of the same element in the agamic division of 
unicellular bodies as in Protozoa makes it comparatively easy to ex- 
plain 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 unicellu- 
lar, 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 cells to the original aga- 
mic mother cell which has disappeared in them may be considered a 
manifestation of heredity, it is also a form of growth and readily sepa- 
rable from the more complicated relations of organisms produced by 
conjugation of two forms. When the transmission of likeness is com- 
plicated with the effects of conjugation the difficulties increase until 
finally in the bodies of the 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 in the budd- 
ing of the metazoa and the parthenogenesis, as in these more compli- 
cated forms, but the phenomena of transmission occurring after con- 
jugation can be separated from growth and considered upon entirely 
distinct lines. 
The theories offered show this. Thus the corpuscular theories, 
whether gemmules or biophors or pangenes are assumed, assert the 
