CLIMBING AND WATER PLANTS 113 



these anomalies are of obvious advantage 

 to a climber, and are calculated to minimise 

 risk of damage to the conducting channels 

 of the stem under the special circumstances 

 of their habit of life. The main stem is 

 sometimes lobed, and it may ultimately even 

 split into a rope-like mass of cordage. Or 

 it may be flattened and wavy in contour, 

 a character obviously associated with con- 

 siderable resilience. Again, the soft phloem 

 is frequently embedded amongst the woody 

 tissues, and is thus shielded from injury 

 such as might arise through torsion of the 

 stem, and in other ways. 



But it is not true that every specialised 

 climber is provided with a special or anomalous 

 stem structure, nor are these abnormalities 

 confined to climbing plants. The facts seem 

 to indicate that the anomalies in question 

 are to be regarded as instances of a break 

 away from traditional structure, that they 

 owe their origin primarily at least to the 

 inner constitution of the living substance of 

 the plants in which they arise. They may 

 be regarded as one of the expressions of 

 inherent tendency to vary which in dominant 

 groups of plants is seen in a multiplication 

 of related species. Any such break away 

 from the type form of structure may prove 

 useful in enabling a plant to develop new 

 functions, or more perfectly to discharge 

 nascent ones. And there are a very large 

 number of instances, of the most varied 



