316 NATURAL SCIENCE [November 
equilibrium in the cells and in the whole organism. Owing to this 
being a labile equilibrium, any disturbance due to an altered 
condition of the environment will alter the ‘set’ of the 
gemmaria and change the conditions of their equilibrium. It is 
as the result of their relation to the organism at large that 
the gemmaria of the reproductive cells R of an organism A are 
compelled to reproduce the likeness of A ; consequently when the 
continuance of altered surroundings alters A to A’, the gemmaria of 
the reproductive cells will get a ‘set’ changing them to R’, which 
will reproduce the altered organism A’, Now, as a formal hypo- 
thesis, this serves to give a very pretty provisional explanation of 
many phenomena of organic life; but we have no sufficient micro- 
scopic evidence in its favour, and, to me at least, much that speaks 
against it. We know too little of the physical relations of cell- 
life to be able to accept, even provisionally, a theory based mainly 
on geometrical and mechanical conceptions. 
The most satisfactory explanation, perhaps, is that put forward by 
Hering and Samuel Butler,! the latter of whom has written with 
singular freshness and an ingenuity which compensates for the 
author’s avowed lack of biological knowledge. This theory has 
indeed a tentative character, and lacks symmetrical complete- 
ness, but is the more welcome as not aiming at the impossible. 
A whole series of phenomena in organic beings are correlated 
under the term of memory, conscious and unconscious, 
patent and latent. Our memory is conscious, when we say a 
lesson or remember a birthday; unconscious, when we let our 
fingers play of themselves a piece of music of which we could 
not write down a note; patent, when we remember to call at a 
friend’s house; latent, during the interval while the servant is 
waiting at the open door, until the sight of the familiar stick, in 
the hall recalls the owner’s name which would not recur to our con- 
sciousness. Of the order of unconscious memory, latent till the 
arrival of the appropriate stimulus, is all the co-operative growth 
and work of the organism, including its development from the repro- 
ductive cells. Concerning the modus operandi we know nothing: 
the phenomenon may be due, as Hering suggests, to molecular 
vibrations, which must be at least as distinct from ordinary physical 
disturbances as Roéntgen’s rays are from ordinary light, or it may 
be correlated, as we ourselves are inclined to think, with complex 
chemical changes in an intricate but orderly succession. For the 
present at least the problem of heredity can only be elucidated by 
the light of mental and not material processes. 
QueEEN’s ConiEeceE, Cork. Marcus Harroe. 
‘ “©On Memory as a Universal Function of Organised Matter” (Vienna, 1870, ex. 
S. Butler in ‘*‘ Unconscious Memory,” p. 97). 
