12 Furure Boranist. 
this season I can only shew you Mimulus and this Fuchsia. 
The effect is to produce a mosaic which nearly fills the space 
exposed. One must, however, remember that it is the plane at 
right angles to the sun’s rays that must be studied. Thus, to see 
the mosaic of leaf-work on a vertical wall, you must look down- 
wards, standing about as far from the wall as your own height. 
The second point, the protection of leaves from injury by too 
strong sunlight, is not so easily seen in this country, but it can be 
traced, for instance, in the position of the black poplar leaves, which 
are hung with their flat surface vertical so that they are edgewise 
to the sun. ‘The same arrangment may be seen in the blue gums 
and other Australian trees, which, in consequence, give but little 
shade. I think the position of the young leaf surface in all our 
British plants is worth investigation. 
I have already alluded to the necessity of rain-water being 
rapidly and quickly conducted off the leaves as explaining the 
smooth, glossy surface of Rhododendron and laurel foliage. If 
you compare these and other evergreens with an ordinary deciduous 
leaf, such as that of the chestnut, for example, the difference is 
most remarkable. The latter has roughnesses, hollows, grooves, 
and scattered hairs, all of which might afford a lodement for 
fungus, spores, and bacteria. This is the beginning of the sub- 
ject, however, for if you watch rain-water falling on any plant, 
you will find that in some cases it is conducted carefully from leaf 
to leaf till it reaches the outside circumference of the shadow. In 
such a case (as i the foxglove or chestnut) the roots spread out 
horizontally, so as to be directly under the drip. In other forms 
the rain-water is conducted down the leaf-stalk to the stem, and 
trickles down until it reaches the root, which in these species is 
usually long, or rather deep and vertical (Chickweed, Woundwort). 
Sometimes the stem is grooved, or the leaves have stipules or 
auricles, which assist in directing this stream in a definite direction. 
A good example is the so-called ligule of grasses, which prevents 
rain with germs and spores from entering the sheath in which the 
tender, growing part of the stem is enclosed. Nothing is known of 
the arrangements of most of our British wild flowers. Sir 
John Lubbock has shown that stipules are used to protect the 
bud either of the leaf or the growing point of the stem. The 
common rock-rose protects its bud by them, but those species of 
rock-rose which are without these organs protect the bud by hairs 
