1 Auve., 1898. ] QUEENSLAND AGRICULTURAL JOURNAL. ‘. 165 
must be carried on, this is performed by the green cuticle of the stem. We 
would naturally expect a plant equipped in this way to be a dweller, when at 
home, in a rocky, sandy soil, where rain seldom falls, and then sparsely. And 
we find that this is the case. It is generally possible to tell from even a 
cursory examination of the appearance and structure of a plant under what con- 
ditions it will thrive best, because every plant is so organised as to make the very 
most of the conditions under which it is naturally found. Take, forinstance, our 
friend the Euphorbia, which we are just discussing. Not only are the leaves sup- 
pressed, so that too much moisture shall not be sent off under the pitiless rays of 
the scorching sun as it beats down on the sandy plains of Mexico, but there is a 
reserve store of moisture saved up, not for the proverbial rainy day, but for a 
long drought, in what are known as the lactiferous vessels in the stems. If 
you cut one of these stems, the milky fluid gushes forth. Very many plants 
jmown as succulent plants, which include a good many Euphorbias, have this 
store of moisture in readiness to carry them over an adverse time, and for this 
quality they have been compared to the camel among animals, which carries 
with it the saving of a time of plenty for the day of need. The resemblance 
is heightened by the fact that they are found usually in the same situations as 
the “ship of the desert.”’ 
The Wild Pineapple (Bromelia sylvestris) close by will catch your eye. 
It grows rapidly, requires little rain and no attention, looks well, and, being 
armed with sharp prickles, makes a capital barrier—at least against those 
plagues of public gardens, the persons who appear to take a delight in 
walking across borders, &c., sometimes to save a few yards’ walk, but chiefly 
for no reason except that it is wrong. 
A. plant close by, and still in the same border, should be much more 
cultivated than it is, if only for the fact that it requires so little attention. 
Tt is that tall flag-like plant, and is known as Adam’s Needle (Yucca gloriosa). 
The spike of white flowers produced by this plant is really beautiful. It does 
not produce seeds outside of its native home unless artificially fertilised, and 
the interdependence of the floral and insect worlds is so well illustrated by this, 
that the words of the great botanical authority, Anton Kerner von Marilaun, 
are well worth quoting. He says—‘“ Certain small moths which visit the 
flowers of Yucca bring the pollen to the stigmas and force it into the stigmatic 
orifices in order that mature fruits and seeds may be produced from the rudi- 
mentary fruits, a result which is indeed a matter of vital importance to those 
moths. For the moths lay their eggs in the carpels of the Yucea, and from 
the eggs larve are developed, which live exclusively on the seeds of this plant. 
Tf the Yucca were not fertilised, and did not develop any fruit, the larve 
would die of hunger.” ‘Truly a wonderful arrangement! This is not by any 
means an isolated case of the kind. Very many plants are persistently untertile 
outside of their native countries, not because the climate does not suit them, 
but simply because the proper kind of insect is not present to secure 
fertilisation. 
At the base of the Yucea and slightly in front you will notice some plants 
having oval leaves, about 25 inches long, with a whitish blotch in the centre. 
This is called the Telegraph Plant (Desmodium gyrans). It got its name 
of ‘Telegraph Plant from the old semaphores which were formerly used for 
transmitting messages across country, and which consisted of an upright post 
with two arms, the changing positions of which indicated the message. If 
you look at the bases of the leaves of this plant ou a bright sunny day, you 
will see that there are two little leaves projecting from the base of the larger 
one. These are known botanically as stipules. 
M 
