reg: NOTES AND COMMENTS. 83 
word ‘‘ Vitalism” has been born. Some time ago, we were all taught 
to regard the human bodyas a machine. In digestion the processes 
were regarded as simple chemical processes: in assimilation the in- 
testines and the vessels were membranes obeying the laws of osmosis 
and dialysis. Respiration was a simple interchange of gases under 
conditions that could be paralleled with glass tubing and physical 
apparatus. Now, all this is given up. The elements of the machine 
are living cells, and the protoplasm of the living cells refuses to act 
as a piece of apparatus, but remains isolated from, unaccountable to, 
the laws of physics and chemistry. So, says the new physiology 
you must give up attempts at chemical and physical explanations ; 
not only are they erroneous but fatally misleading. Protoplasm 
must be studied as a thing of its own kind; its own facts taken 
by themselves; its own empirical laws sought after. 

TROPICAL SEEDS IN THE HEBRIDES. 
In the December number of the Annals of Botany (vol. vi., p. 369), 
Mr. Hemsley gives an account of a drift-seed of the tropical [pomea 
tubevosa which reached the Hebrides, probably from the West Indies, 
by the agency of the Gulf Stream. Only one instance is recorded, 
but from the fact of its having in Long Island a Gaelic name, signi- 
fying Mary’s Bean, it would seem that its appearance on their shore 
is not an extreme rarity. 
PHYSIOLOGICAL ACTION AT A DISTANCE. 
In the same number of the Annals (p. 373), Professor Léo Errera, 
of Brussels, communicates an interesting note on the Cause of 
Physiological Action at a Distance. This term was used by Elfving 
to explain some phenomena of attraction and repulsion which did 
not seem to belong to any of the known categories of geotropic, 
heliotropic, hydrotropic, &c. He found that pieces of iron and, to a 
less degree, of zinc or aluminium, as well as different organic sub- 
stances, such as sealing wax or resin, attract the growing sporangium- 
bearing filaments of the well-known fungus, Phycomyces nitens. All 
other metals tried were inactive, and the filaments of Phycomyces itself 
showed a mutual repulsion. 
From careful experiments, Professor Errera concludes that this 
apparently mysterious action is merely a matter of hydrotropism ; 
hydrotropism (negative or positive) being the bending of a plant- 
organ towards the point, not where it will find a minimum or 
maximum of moisture, but where it will, within certain limits, lose 
(by transpiration) the greatest or least amount of water. Knowing 
that a surface which emits moisture repels the Phycomyces filaments, 
it seemed probable that moisture-absorbing substances would produce 
the reverse effect, and attract them; and as iron certainly absorbs 
aqueous vapour when rusting, its action on the fungus filament might 
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