PRESIDENTIAL ADDRESS. 447 
cotitinuity of the germ plasm and the comparative unimportaince from the 
standpoint of heredity of somatic qualities, as well as the non-inheritance 
of mere environmental effects (acquired characters), are all necessary con- 
sequences of the view I have advanced. 
The general similarity of structure throughout organised creation may 
well be conditional primarily by properties inherent in the materials of 
which all living things are composed—of carbon, of oxygen, of nitrogen, of 
hydrogen, of phosphorus, of sulphur. At some early period, however, the 
possibilities became limited and directed processes became the order of the 
day. From that time onward the chemistry prevailing in organic nature 
became a far simpler chemistry than that of the laboratory: the possibilities 
were diminished, the certainties of a definite line of action were increased. 
How this came about it is impossible to say; mere accident may have led 
to it. Thus we may assume that some relatively simple asymmetric sub- 
stance was produced by the fortuitous occurrence of a change under con- 
ditions such as obtain in our laboratories and that consequently the 
enantiomorphous isomeric forms of equal opposite activity were produced 
in equal amounts. We may suppose that a pool containing such material 
having been dried up dust of molecular fineness was dispersed; such dust 
falling into other similar pools near the crystallisation point may well have 
conditioned the separation of only one of the two isomeric forms present in 
the liquid. A separation having been once effected in this manner, assum- 
ing the substance to be one which could influence its own formation, one 
form rather than the other might have been produced. An active substance 
thus generated and selected out might then become the origin of a series 
of asymmetric syntheses. How the complicated series of changes which 
constitute life may have arisen we cannot even guess at present; but when 
we contemplate the inherent simplicity of chemical change and bear in 
mind that life seems but to depend on the simultaneous occurrence of a 
series of changes of a somewhat diverse order, it does not appear to be 
beyond the bounds of possibility to arrive at a broad understanding of the 
method of life. Nor are we likely to be misled into thinking that we can 
so arrange the conditions as to control and reproduce it; the series of lucky 
accidents which seem to be required for arrangements ‘of such complexity 
to be entered upon is so infinitely great. 
The ovum and the spermatazoon must be supposed to have all the direc- 
tive influences stored up in them which are subsequently brought into play 
in the development of the organism; they may be looked upon as bundles 
of templates of very definite structure. As both paternal and maternal 
qualities may be handed on to the offspring, and as there is so near an 
equality of the sexes in the higher organisms, it appears likely that the 
male and female elements are produced in equal numbers by both parents, 
either the one or the other becoming developed at conception, according to 
the accidents of the moment, whereby both the sex of the offspring is deter- 
mined and whether it be primarily derived from the one or the other parent. 
There cannot well be complete interpenetration of the two elements: 
rather is it to be supposed that surface contacts are established which lead 
to transferences from one to the other chromasome; to use vulgar terms, 
that eyebrows are pencilled, the nose straightened, narrowed or broadened, 
hair made fair or dark; that by interpenetration of the curls this or that 
other quality is modified by a molecule being plastered on here, another 
smoothed off there, while cross-connexions are established in some direc- 
tions but broken in others. 
Such a picture cannot be regarded as extravagant. We may even claim 
literary appreciation in support of our temerity—no less a writer than 
Emerson, for example, as witness the following passage in his ‘ Uses of 
Great Men’ :— 
