12 MICHIGAN ACADEMY OF SCIENCE. 



of enerjiv. as of siiniile lieat, oombiiuitiou occurred. From the simple 

 arose the slijihtly complex. From complex to more complex we pass 

 as new combinations of energy act, until at length we reach the acme 

 of comiilcxity — that sul»stan<e supremely complex, hence supremely un- 

 stable, that substance that gains only to lose and loses in the act of 

 gaining, protoplasm. Not protoplasm as we know it today, for proto- 

 plasm has become profoundly modified, but protoplasm simpler, the 

 actually simjtle substance organized by i»hysical and chemical forces 

 alone, but structureless in the sense that it is homogeneous throughout,, 

 only of enormously intricate molecular organization. This simple proto- 

 plasm, through the aid of forces from without plus the energies gained 

 by its internal changes, assimilates and grows. As it increases in bulk 

 its gain in surface lags behind its increase in volume. But assimilation 

 must occur through the surface, unless assimilation occur it must 

 break down and laj^se into the inorganic again. The surface, then 

 must increase; ]ierhaps by thinning out as into a sheet, but surface 

 tension tends to bring it to the spherical form and it can and does best 

 effect the end by division into a number of parts — two, three or any 

 number of them. Note well that this is the result of unfavorable 

 nutritive conditions. 



We are accustonuHl to think of sexuality as the highest development 

 of the living thing, as occurring at the maturity of an organism, at its 

 limit of growth, when those forces that have built it up are no longer 

 able to increase its size. But sexuality rests back on reproduction 

 and we here trace re]troduction to its limit and find the same thing 

 characterizing it that has inhered in all subsecjuent development. 



Now the evolution of the cell and its elements occurs, the origin of 

 organism. A )-ai»id sketch must suffice: — stimulus at any point produces 

 reaction of tlu^ whole — stimulus jiaths occur throughout the mass, the 

 outside responds to stimulus directly, the inside indirectly — in the 

 interior the results of varied stimuli first encounter each other and are 

 composed into a resultant effect — coordination arises — a nucleus is born 

 — reactions become stored as ex])erience — specialized portions repre- 

 senting a physical cell-memory are produced — by the aggregation of these 

 is formed the heredity apparatus, chromomeres and chromosomes — a 

 cell-memory for division arises, though it seems not to have been fully 

 localized, in all cases, in a centrosome, etc., etc. 



Division, the result of food-scarcity, is reyu'oductiou. To preserve 

 itself in unfavorable conditions binary and multiple divisions are sifted 

 out by natural selection. Other things being equal, size is an advantage. 

 By binary division the greatest size of the resultant cells is gained, 

 together with a moderate increase of surface and nutritive power. In. 

 multiple division the bulk is indeed less, but there is relatively very 

 great gain in surface, hence great nutritive power and great i)Otential 

 activity. Little food is needed to nourish so small a body, but it has 

 great alnlity of gaining it. In this case we have. then, instead of a 

 starved, a better jtrovided organism. Thus arises reproductive, though 

 not yet sexual, dimoriihisni. Let us for a moment consider reproduction 

 as it obtains among the lower forms today. 



In A'orticejla fei'tilization is often attained by the breaking up of an 

 individual into a number of smaller cells that swim oil', and, seeking a 



