July i, iSgi.l 
THE TROPICAL AGRICULTURIST. 
31 
caterpillars. What was to check the tendency of the 
numerous enemies of tlie vegetable kingdom from 
destroying many types of plant life. Years ago it 
was imagined hy some people that the existence 
of thorns and thistles could oe best accounted for 
by the theory of the original transgression. Hut 
botanists knew tliat this had practically nothing 
to do with the subject. Thorns and thistles were in 
the world long before the creation of man; and if 
people chose to take a too literal view of many things 
m the Bible, they would find themselves in error in- 
stead of in truth. The fact was that both thorns 
and thistles were natural defences against the enemies 
of many kinds of flowering plants, belonging to 
various orders all over the world. These defences 
were perhaps most strongly developed in tropical 
countries, wnore the battle of life was fought more 
keenly and fiercely than in temperate regions. Jjook. 
said the Doctor, upon the enormous number of 
substances secreted by the leaves, stems, roots, 
and fruits of plants. Sometimes the plant’s defence 
would be its prickles or thorns to prevent mammalia 
browsing upon them, and slugs and snails from 
climbing up their stems — such for instance as the 
bramble, whose re-curved hooks also servo the 
purpose of grappling irons to enable the plant to 
climb by. Thorns were sometimes promieed as 
stiffened hairs, as for instance in the gooseberry; 
others had stipules converted at the base into the 
same defensive material, as in the acacias. In tlie 
hawthorn the branch itself was aborted into thorns. 
Reference was made to the thistle, one of the 
finest armed plants and th.e most mechanically 
perfect in the whole world. Then, said the Doctor, 
the loaves of some plants were sour, like the 
sorrel and mountain sonel, which contained oxalate 
of potash, which was really a poison, and thereby 
prevented slugs from eating the leaves. Some- 
times the leaves were intensely acrid, like the 
buttercup and lords and ladies (Arum mafula(iiiii). 
The buttercup family was intensely poisonous all 
over the world, and he called to their mind how 
they would see in the dry summer time, when all 
the gras.s was close cropped, clusters of buttercups 
untouched by the cattle. The order of plants to 
which the tobacco belonged secreted poisonous 
materials — indeed, humorously said the lecturer, if 
the tobacco plant wore not so’ it would not have been 
worth smoking, [l.aughter.l lie reminded them that 
this peculiar order was objectiorahlo to most herb- 
feeding animals, for instance, the tomato and the 
berries of the bitter sweet [ftolanvm dvicawaru.) Tlie 
poisonous character of the henbane (Bi/csci/amus) and 
the belladonna, etc., The poppy secreted opium and 
protected itself thereby. Sparrows, he explained, 
would feed upon the flowers of the crocus, but they 
would not touch the loaves and rarely the roots. 
The hawthorn, the flowers of the almond tree, and 
the meadow sweet contained prussic acid. Many 
plants, especially the grasses, protected themselves 
by secreting a vast amount of silica in their skins. 
Other orders, lilco the crucifer, had both roots and 
leaves intensely pungent, as in the case of the radish, 
mustard and cress, etc. Some were intensely bitter, 
like the ferns, and these latter were seldom eaten 
by any animal, 't'lie tannin in the bark of trees pro- 
tected them against the gnawing haliits of mammalia, 
and the bitterness of the strychnine in our gentinn 
family, several of which were used by medical men 
as tonics, was remarkable. ’J’he lecturer then wont 
on to notice that even the perfume and odours of 
plants, such as the loaves of the sw'eet briar, mint, 
wild thyme, sage, itrc., were more or lees protective 
agencies not so much against animals as against the 
auii, for it 18 a tact that these perfuiiies kept the 
atmosphere cool, and they might often see sweet 
smelling plants flowering 111 the scorching sunshine, 
when those plants not so endowed were 
withered by the fervent heat. The Doctor illustrated 
these various phenomena by sketches upon the black- 
board, as well as by coloure d diagrams, 
PARASITIC flowering PLANTS. 
. Dr, Taylor passed on to another part of his sub- 
ject, and an exceedingly interesting portion, namely. 
that of the flowering plants, belonging to what he 
called highly exalted orders which got their living 
by preying upon, robbing, and even miirdcriug the 
neighbouring plants. These remarks were illustrated 
by a series of mounted specimens of the broomrapes, 
which were found in abundance on every common, 
and were only too well known to every farmer from 
their attacks upon his clover field. The collection 
had been made by Captain Haward, of Little 
Blakenham, and it showed one species of the broom- 
rape attacking fourteen kinds of different flowering 
plants. Vegetable parasitism could be found in every 
stage. Some species only occasionally indulged in 
it ; others, like the broouirape and dodder, could not 
live in any other wav. The dodder belonged to the 
order of the convolvolus. If a seed were put in the 
ground, it would develop a couple of small leaves and 
a long, slender, sensitive stem. They might see it 
waving about as though it were trying to feel out for 
something. If it did not find anything, the plant died; 
if it came into contact with any succulent plant, 
it climbed it, and develope suckers which fed upon 
their host in such a manner that the substance 
of the latter was drawn off into its structure. 
When the dodder stem had once got a good hold it 
let go of the earth, and henceforth lived entirely 
upon the plant which it had embraced. The dodder 
killed off thousands of acres of crop plants every 
year. The broomrape sometimes attained a height 
of IS inches; it had no roots, except one, which 
crept out in search of some adjacent plant until 
it came in contact with it when it fused itself with 
its victim beneath the soil. What a great vegetable 
bully it was, sometimes five times as largo as the 
plant upon which it levied blackmail. The broomrape 
had remnants of its former leaves brown and shri- 
velled that wore not used, yto that it even did not 
get the carbon from the atiuosphere. The mistletoe 
was another parasitic plant. Its home was in Australia, 
where the huge gum trees there sometimes contain 
mole mistletoe foliage than their own, but the 
mistletoe did obtain its own carbon. Then there 
were other vegetable murderers, particularly in the 
tropics, that twisted their stems so rounci other 
trees as to strangle them. It was impossible to 
go into a tropical forest without being painfully 
impressed by the reckless selfishness and craftiness 
of numerous members of the vegetable kingdom. 
In Brazil, one of those llianas, or climbing plants, 
was called the murderer, because it actually spread 
out its stem broadly round the tree it climbed by, 
so as to complotoly encase it, and the living plant 
often supported within its embrace its dead and 
murdered victim. The ivy was also referred to. 
Space forbids us to enumerate other types of plants 
in different parts of the world which illuetrated the 
lec turer's theory of the selfislmess, craft, and seem- 
ing cruelty of those members of the vegetable world 
which did not get an honest living by their own roots 
and atoms and leaves, hut whose existence depended 
up.on the ingenious, sagacious, but immoral practice of 
these expedients of craft . — Ipswich paper. 
A New Minkbal.-Uc. H. A. Miers in the d/iKc- 
rahgical Magazine, describes a new mineral, which 
has u.ea named “ Sanguinite." It was observed 
cn neoirneeB of argentine from Chafisroillo, and 
i.s probably a hexagonal eulpharsenite silver 
allied to proustite. To the naked eye the mineral 
i!) pcarod to bo gbthite, but examination with the 
imciosoopo revealed ils different character. It has 
lustre, like earthy hematite ; colour, bronza-red 
by refleuted light, srrd blood-red by transmitted 
lit ht ; streak, dark, purplish brown. No quacli- 
tEtive examinntiori was made, on aooount of the 
Rinall quantity of material ; a qualitative analysis 
however, showed the presenoe of silver, arsenic' 
and sulphur. The physioal characters as a whole 
prevent the mineral from being referred to 
proustite or xanthooonito, the mineral being nearer 
like the former in its physical oharaoterl The 
specifio gravity and hardness have not been de- 
termined . — Public Opinion. 
