312 | ANNUAL REPORT SMITHSONIAN INSTITUTION, 1944 
there has been a closer approach to mastery that approach has been 
accompanied by a greater division of labor and a closer coordination 
of the constituent units until in man, the master, they have become 
woven into an intricate pattern of cooperating parts. At the opposite 
extreme lies an ineffectual, single-celled droplet of living material 
exemplified by Amoeba. Organic evolution is thus history, as much a 
part of our history as is the history of the written word, and as such, 
in fulfilling one of its functions, it points out the road we have trod 
and lights the way that les ahead. 
I am a zoologist, but for a moment I should like to turn Tey 
that man who has been termed by Schlegel a prophet looking back- 
ward, and as such a prophet refresh your memories by briefly tracing 
the steps of this story as others have done before me. 
It can begin with Amoeba, a creature which epitomizes individual- 
ism. Not even in the commonly shared function of reproduction is it 
dependent upon another for assistance. A thousand and one changes 
have been rung on this isolationist-individualist theme among its fellow 
protozoans, each change having brought survival but no shred of 
mastery. 
One of the early mutations leading out of the protozoan doldrums 
was that which resulted in causing proliferating cells to remain clus- 
tered together, and as such clusters to cooperate in the form of tubular 
units; a condition exemplified in varying degrees by the Porifera and 
the Coelenterata. The rewards were those that come from numbers | 
and elementary divisions of function. This condition was followed 
by an innovation which resulted in dense, compact and solid masses 
of cells being able to exist as a single unit exemplified by our friends 
and tormentors, the flatworms. This state of affairs was accompanied 
by greater diversification in the constituent units and preeminently 
by rectilinear locomotion. 
The next steps—three of them—in this mutating series were par- 
ticularly significant ; the development of distance receptors, the device 
which produced essentially compound animals, and the accompanying 
delegation of authority to subcenters which thus made possible the 
rapid and efficient control so characteristic of the metameric groups. 
Metamerism is as far as life has gone in the way of physically com- 
pounding units. The compounding has continued but on the psycho- 
logical level, or social level if you wish. If we are to consider 
psychological reactions as a specialized manifestation of physiological 
states, the continued compounding which we term our social organiza- 
tion is fully as much a physiological process as were the physical 
unions just outlined and as such must be considered a direct con- 
tinuation of this compounding tendency, a continuation made pos- 
sible by the development of distance receptors. 
