TRANSACTIONS OF SECTION D. 539 
phosphorus, they may be said to constitute the chemical and physiological wealth 
of the plant. On this account they must be carefully guarded from any external 
influence that would degrade their chemical constitution or lead to a misappro- 
priation of the nutritious matters they contain. Now it is well known that the 
leaves and stems of nearly all plants are subject to the attacks of parasitic fungi. 
The spores of these parasites germinate on the leaves of the plant on which they 
alight, and appropriate its juices to their own use, as, for example, in the case of 
the fungus which occasions the potato disease. All kinds of moulds, putrefaction, 
and fermentation are in like manner produced by the development of spores 
falling from the atmosphere which have found a favourable soil for their growth. 
Now a more suitable pabulum or nidus for the growth of mould-germs can 
hardly be imagined than that which would be afforded by the immature ovules, 
seeing that in them is collected a large amount of easily assimilable matter 
destined for the nutrition of the embryonic plant. There can be little doubt then 
that the disadvantages which the pistil brings with it, and the higher organisation 
thereby entailed, are more than compensated for by the security which it gives 
against the entrance of fungus spores. ‘The pea pod is in fact the counterpart of 
the hermetically sealed or stoppered flasks in which Tyndall and Pasteur performed 
their well-known experiments on the preservation of organic fluids against putre- 
factive changes. These observers found that it was possible to preserve beef-tea 
or other organic infusion, for any length of time, provided no air was admitted to 
the flask, or if care were taken to filter the air from all organic germs, by passing 
it through cotton wool, &c. before allowing it to have access to the infusion. The 
pistil of a flower then may be regarded as analogous to the flask in these 
experiments. The loose cellular substance of the style, and the acid secretion on 
the stigma, may in like manner serve to filter the air before it reaches the ovules 
contained within the ovary. At any rate, the air must pass through the substance 
of the carpels before it can reach the ovules. This view of the function of the 
carpels is corroborated by the fact observed in the case of Reseda, the carpels of 
which open soon after fertilisation. After dry weather an accumulation of sand and 
dust frequently takes place within the ovary of Reseda. When this fact is viewed in 
connection with the experiments of Van Tieghem, which show how difficult it is 
to effect the direct fertilisation of ovules with pollen, owing to the constant appear- 
ance of microscopic fungi, a new light is thrown on a vast number of vegetable and 
animal structures. The same principle operates, not only among phanerogams, but 
even among the cryptogams; nor could a principle of such general application 
in the vegetable world have failed to play an important part in the animal 
kingdom. It is remarkable then to find that within the cup of the commonest 
wild flower we have the results of recent scientific research anticipated, the 
benefits of the antiseptic system as completely secured as by modern surgery, and 
a parallel between nature and art which agrees even to the minutest detail. 
MONDAY, SEPTEMBER 24. 
The following Reports and Papers were read :— 
1. Report on the Record of Zoological Literature. 
2. Report of the Committee for aiding in the maintenance of the Scottish 
Zoological Station.—See Reports, p. 233. 
3. Report of the Committee for arranging for the Occupation of a Table at 
the Zoological Station at Naples.—See Reports, p. 234. 
