CLIMBING AND WATER PLANTS 125 
that it is only an apparent, and not a real 
risk. The fact is, the veins form a beautiful 
system of unions or anastomoses, and these 
are often arranged in a series of arches which 
pass just under the indentations characteristic 
of the leaf margins of so many plants. 
There are certain exceptions, however, to 
the general rule that leaf construction is 
adapted to prevent tearing. All palms have 
leaves which are primarily undivided. But 
by complicated processes which result in the 
dying out of strips of leaf tissue extending 
from the midrib to the margin, the leaf 
surface as a whole may be broken up into 
strips resembling pinne or leaflets. This 
occurs in the Coco-nut, and many other 
palms. These “leaflets”? are very different 
from the true leaflets of a vetch and most 
other plants, where they arise as the result 
of a true process of branching. The so-called 
fan-leaved palms have leaves in which there 
is no great elongation of the “ midrib,” and 
the pleated or concertina-like folding represent 
the imperfect separation of the “leaflet” 
which is only completely carried out in forms 
like the Coco-nut, Areca, and other pinnate- 
leaved species. 
The Banana plant is especially interesting 
in this connection, for it is provided by 
nature with a leaf quite unsuitable for a 
plant growing in any but the most sheltered 
situations. The banana plant consists of a 
thick herbaceous axis, sheathed by the bases 
