LIBRARY, 
FEB24189? 
[.Read before the Texas Academy of Science, December , 1<9R5.] 
MOLECULAR THEORIES OF ORGANIC REPRODUCTION. 
BY DR. EDMUND MONTGOMERY. 
Organic reproduction may well be called the supreme marvel of phys¬ 
ical nature. Out of a single nucleated cell, structurally all but undiffer¬ 
entiated, issue in preconcerted order the myriads of specifically diversi¬ 
fied constituents that build up the wondrously organized frame of higher 
organisms. And the various reproductive germ-cells of these, hardly 
distinguishable one from the other, contain in some way prearranged 
with rigorous precision the potential forecast of the entire series of evo¬ 
lutional changes that lead in the one case, say to the construction of a 
tiny mouse, in another to the construction of the huge and most dissim¬ 
ilar elephant. 
Now what can be the nature of the peculiar process through which so 
minute and homogeneous a speck of matter is made to reproduce thus 
faithfully the complexly organized being from which it is derived ? 
To find a scientifically valid solution of this great problem of repro¬ 
duction and heredity has been the assiduous endeavor of many of our 
foremost biologists. 
The problem has various aspects. Manifold results are reproductively 
attained; physical and psychical, physiological and morphological. 'But 
among these it is chiefly on the morphological outcomes that biologists 
have at present fixed their attention. Starting, as is usually done, from 
the tenets of what is known as the cell-theory, two disparate views of 
the reproductive process undergone by germ-cells have each been advo¬ 
cated by eminent scientists. The one view finds its most elaborated ex¬ 
pression in Darwin’s theory of Pangenesis, the other in Weismann’s 
theory of the Continuity of the Germ-plasm. 
The cell-theory maintains, that the diversified tissues of organic beings 
are all derived from the reproductive germ-cell by a process of cumula¬ 
tive cell-division; the fully developed organism consisting thus alto¬ 
gether of a vast aggregate of more or less differentiated descendants of 
the original germ-cell. The organic individual is consequently looked 
upon as a conglomerate of a multitude of autonomous beings, all the 
progeny of the simple germ-cell. 
In keeping with this view, the fundamental question of reproduction 
