132 
THE WISTARIA SINENSIS. 
layers as before, extending from the bark in which they originate to the lifeless 
surface of the old wood within. It is evident, therefore, that the divergent 
layers are formed, not from the pith, but from the proper juice descending through 
the channel of the bark." 
So Keith expresses himself, when commenting on Knight's experiments, 
which led that profound physiologist to substitute the term convergent, for 
divergent. 
In further proof of the theory, it should be borne in mind that the innermost 
layers of a tree—the true heart- wood— retain some moisture, though the current 
of the annual sap is confined chiefly to the last formed, outward layer, or sap- 
wood (alburnum). The entire body of wood partakes also of a certain portion 
of the specific resinous, oleaginous, aromatic qualities of the bark, although the 
ascending sap has always been nearly void of flavour. 
From analogy of facts it then may be inferred that the medullary processes, 
now called convergent layers, are the media through which the connexion between 
the old wood and the newly deposited layers of alburnum and liber is maintained, 
and that these layers supply the tree by a lateral course, with resinous matters 
which preserve the wood from decay and give it hardness and durability. 
"We shall have occasion to throw more light upon this mysterious function of 
supply, when viewing the offices of leaves, and the laboration of the food, and 
specific fluids of plants. 
THE WISTARIA SINENSIS» 
Every one who has been to either of the May exhibitions of the Horticultural 
Gardens, at Chiswick, within the last few years, has doubtless been filled with 
admiration by the magnificent specimen of Wistaria sinensis on one of the walls, 
which is generally at that time in full flower. And we presume that few who 
have seen it in such an aspect, have gone away without a desire to possess so 
beautiful an ornament. 
Judging from the comparative infrequency of its occurrence in small gardens, it 
would appear not to be known that it propagates so readily as to be purchaseable 
in any nursery for a small sura, and that it may be cultivated with the greatest 
ease, as well as in a considerable variety of ways. In stating these plain facts, 
therefore, and referring to the plant itself as an evidence of its desirableness, we 
shall just glance at the several modes in which it may be advantageously treated. 
As a greenhouse or conservatory climber, its attractions are sufficiently familiar 
and recognised, although, considering its extreme beauty and fragrance, and capa- 
city of blooming several times in one season, besides flourishing in almost any 
aspect, and being by no means particular as to where it is planted, we should 
expect to find it in every greenhouse and conservatory throughout the country. 
