ADDRESS. xix 
neglected by’ some naturalists, and discarded by others, which, under his 
mind and eye, prove to be of first-rate scientific importance. An eminent 
surgeon and physiologist (Mr. James Paget) remarked to me, d@ propos of these 
volumes, that they exemplify in a most remarkable manner that power of 
utilizing the waste materials of other men’s laboratories which is a very 
characteristic feature of their author. As one of those pieces justificatives of 
his previous work, ‘The Origin of Species,’ which have been waited for so 
long and impatiently, these volumes will probably have more than their due 
influence ; for the serried ranks of facts in support of his theories which they 
present, may well awe many a timid naturalist into swallowing more obnoxious 
doctrines than that of natural selection. 
It is in this work that Mr. Darwin expounds his new hypothesis of Pan- 
genesis, which certainly correlates, and may prove to contain the rationale of 
all the phenomena of reproduction and of inheritance. You are aware that 
every plant or animal commences its more or less independent life as a single 
cell, from which is developed an organism more or less closely similar to 
its parent. One of the most striking examples I can think of is afforded by 
a species of Begonia, the stalks, leaves, and other parts of which are super- 
ficially studded with loosely attached cellular bodies. Any one of those 
bodies, if placed under favourable conditions, will produce a perfect plant, 
similar to its parent. You may say that these bodies have inherited the 
potentiality to do so; but this is not all, for every plant thus produced, in like 
manner developes on its stalks leaves and myriads of similar bodies, endowed 
with the same property of becoming new plants, and so on, apparently 
interminably. Therefore the original cell that left the grand parent, not only 
carried with it this so-called potentiality, but multiplied it and distributed 
it with undiminished power through the other cells of the plant produced 
by itself, and so on, for countless generations. What is this potentiality ? 
and how is this power to reproduce thus propagated, so that an organism can, 
by single cells, multiply itself so rapidly, and within very narrow limits, so 
surely and so interminably? Mr. Darwin suggests an explanation, by as- 
suming that each cell or fragment of a plant (or animal) contains myriads 
of atoms or gemmules, each of which gemmule he supposes to have been 
thrown off from the separate cells of the mother-plant, the gemmules 
_ having the power of multiplication, and of circulating throughout the plant : 
their future development he supposes to depend on their affinity for other 
partially developed cells in due order of succession. Gemmules which do 
not become developed, may, according to his hypothesis, be transmitted 
through many succeeding generations, thus enabling us to understand 
many remarkable cases of reversion or atavism. Hence the normal organs 
of the body have not only the representative elements of which they consist 
diffused through all the other parts of the body, but the morbid states of 
these, as hereditary diseases, malformations, &c., all actually circulate in the 
body as morbid gemmules. 
As with other hypotheses based on the assumed existence of structures and 
elements that escape our senses, by reason of their minuteness or subtlety, 
this of Pangenesis will approve itself to some minds and not to others. To 
some these inconceivably minute circulating gemmules will be as apparent 
to the mind’s eye as the stars of which the Milky Way is composed ; others 
will prefer embodying the idea in such a term as potentiality, a term which 
conveys no definite impression whatever, and they will like it none the less 
on this account. 
Whatever be the scientific value of these gemmules, there is no question 
