3o 
THH TROPICAL AGRtCU Lf U R!ST. 
[July i, 189 i. 
. vertically they would see packed away in the centre 
the young plant which was to sprout in the year 
following. Sometimes this stowing away of vegetable 
starch underground would be utilized for purposes 
of propagation. Everybody was acquainted with the 
fact that the potato had so-called eyes, from every 
one of which potato plants would sprout, and they 
could cut up the vegetable with impunity as long as 
they did not injure this eye. This was the case also 
with the tubers of the artichokes. Even as regards 
the leaves, said the lecturer, which were to be 
brought forth next summer, they were already 
formed. If we looked upon any lilac bush, or horse- 
chesnut tree, or, indeed any shrub, we should find 
them crowded with brown buds. If these were cut 
in halves the leaves would be found packed away 
within the protective bracts, which were really modi- 
fied leaves, which never became leaves, but which 
sacrificed themselves, for the sake of the tender little 
leaves which they enclosed. Even the flowers Dr. 
Taylor said, in some instances, that were to come 
next year, had been provided for last season, as in 
the case of the catkins of the hazel which were now 
shedding their pollen from the hedges by the wayside. 
In all these cases the lecturer pointed out that one 
of the most important elements. Nitrogen, which en- 
tered into the composition of plant food, and which 
article we supplied to crops in nitrate of soda, was 
taken by the root hair of the plants from the soil. 
We were surrounded in the atmosphere by a huge 
reservoir of nitrogen, composing 79 per cent of the 
constituents of the atmosphere. No order of plants 
however except the podded plants like beans or peas, 
had the power of tapping this vast aerial supply. 
But supposing, said the Curator, that plants were 
so situated that these roots could not penetrate 
the soil to obtain any of the nitrogenous 
materials which the soil contained. The only means 
by which the soil was refreshed was by the dead 
bodies of animals, both great and small. Mother 
Earth had been for millions of years receiving back 
to her bosom the children to wliich she had given 
birth, microscopically small, and gigantically large. 
Sometimes, of course, the soil was refreshed from 
the atmosphere, as during thunderstorms, when the 
lightning flash had the power of combining in its 
path the nitrogen with the oxygen, and producing 
thereby fertilising nitrous oxide. The soil contained 
hosts of bacteria, which were engaged in the work 
of converting decomposing matter which contained 
nitrogen, so that it should be soluble for the root 
hairs of plants; nitrifying the soil, in short. Now, 
he said, there were groups of plants whose nature 
had been only studied during the last twenty years, 
which now vs'ent by the name of carnivorous or in- 
sectivorous. Most of them lived in marshy spots in 
various parts of the world. These plants, as a rule, 
had roots which were simply so many anchoring 
threads, to prevent the plant being blown away. So 
the duty of obtaining nitrogen was thrown upon the 
leaves, and these leaves, in the process of the battle 
of vegetable life, and the keen strife that had been 
going on for ages past in the vegetable kingdom, de- 
veloped special powers of capturing animals — that is 
to say, insects of all kinds, small fish, and even birds. 
The lecturer refered to, first, the sundew, of which 
we have three species in England. This plant was 
found in both North and South America, the Cape of 
Good Hope, and other places, but it was most prolific 
in Australia, where there were no less than forty 
kinds. All of thein possess the power of capturing, 
strangling, and even digesting insects which visited 
them. By means of diagrams he pointed out the 
structure of these curious plants, showing how a 
rosette of green leaves, which were crowded with 
tentacles, t)jat were really only portions of leaves 
extended like the fingers of a glove, secreted dew- 
like drops, and the greater the sunshine the greater 
the quantity of this glutinous material. They were 
exceedingly sensitive to anything touching them of 
a nitrogenous nature. One oiglity-thousandth part 
of a gram of ammonia affected thciii. The tentacles 
would then flex themselveB over and show that they 
were influenced. Microscopic examination showed 
the protoplasmic stream in agitittigu under uitj;o- 
genous stimulancy. Insects, in proportion to their 
size, contained more nitrogen than any other kind of 
creature. Along our hillsides sometimes they would 
see in the boggy districts a large area of the country 
crowded with sundews, the most remarkable plant of 
our British flora, and insects would be attracted by 
the sparkling dew to have a drink. When they alighted 
upon the leaf the hapless creature would be 
entangled among the glutinous, viscid matter, so as to 
be unable to get away. Then the tentacles would 
flex themselves over it, the edges of the leaf would 
curl up, the insect would be strangled and suffocated. 
Decomposition would set in, and the leaves actually 
possess the fluid pepsine like the human stomach, 
by which it could digest the nitrogen and assimilate 
it. Then the tentacles would turn to their old position, 
and the empty case of the insect would be blown or 
washed away. The Doctor then related various ex- 
periments which he had made on these carnivorous 
plants. Another plant growing on our hillsides was 
the butterwort, so called from its rosette of greasy 
leaves. There were certain kinds of insects called 
plant lice, which when they attacked the leaves of 
this butterwort slipped about its surface like a lanky, 
bad skater. These plants had also the function for 
digesting these insects which the leaves had captured. 
He next described an aquatic carnivorous plant 
which was to be found in the River Gipping, and 
they might often have seen its yellow spikes just 
appearing above the water level. They were regular 
eel traps as regarded their structure ; minute water 
flies or the larv:B of fish could get in but they could 
not get out. They were strangled and digested. 
The Doctor then referred to the great pitcher plants 
of the Malay Archipelago, so huge that sometimes 
they held half a gallon of water, in shape they 
were like a hot-water jug with the cover half lifted. 
Small birds frequented them to drink, but having 
partaken, v/hen tliey strive to get out they are 
driven back by two large pointed spikes, until at 
length they are drowned, in the liquid there were 
actually bacteria present, which helped to decompose 
the birds, and in this way the nepenthus plant 
provided itself with nitrogen. In North America 
there was the side-saddle plant, the sarnacenin and 
daiiingtonia, which also caught flies on their pecu- 
liar and suggestive manner, so that the interiors 
of their trumpet-shaped entrances were frequently 
crowded with flies, dead and dying. Singularly 
enough these plants not only had a bright attractive 
colour at the upper part of the trumpet-shaped tube, 
but they also secreted honey, and a fly lighting 
upon it might imagine that it was quite safe to 
sip. It got sweeter lower down. The interior, 
however, was covered with hairs, which grew down- 
wards, and when the insect tried to come back it 
dropped to the bottom, to join its foolish brethren 
who had come the same way. They were decom- 
posed within, and thus the side-saddle plants of 
America, through their modified leaves as pitchers 
and trumpet-like tubes, fed themselves in this remark- 
able manner. 
THE DEFENCES OF PLANTS. 
The immediate subjects of the lecture were in 
touch with those treated on in previous discourses, 
although of a distinctly individual character. Dr. 
Taylor brought before his hearers n the first instance 
the subject of the defence of plants. Prom what he 
had said concerning the usefulness of green leaves 
it would be seen that the loss of a single leaf was 
decidedly injurious to the plant. He asked them 
to consider the vast number of enemies which plants 
had to cope with, for it might be said that the whole 
animal kingdom depended for its existence 
upon the vegetable. Not only did mammalia browse 
upon herbaceous plants, but the larvse of untold 
millions of insects did so too. In addition to these 
were the slugs, snails, &c., which fed entirely upon 
vegetable structiu-es. Perhaps numerous spare leaves 
on every tree were provided for the sole purpose of 
meeting the demands of the animal kingdom. It is 
no unoom. »on thing during a droughty summer, 
to see the ground and the hedge rows stripped of 
thQir l^av^s entirely through the depredatioas of 
