PRUNING EXOTIC PLANTS. 
33 
from the roots. A second spring exhibits buds, one between each pair of stipules ; 
the wood of the entire stem being perfectly firm, the tint olive green tinged with 
russet, and with every mark of health \ but as yet the experiment has not been 
carried further. 
On the subject of Stipul(B^ or stipules. Dr. Lindley 
says they " are attached to each side of the base of the 
petiole. They have, if leafy, veins, the anatomical 
structure of which is the same as that of the veins of 
the leaves." " Stipules are sometimes transformed 
into leaves ; they sometimes have buds in their 
axils, and may be therefore considered rudimentary 
leaves." 
The annexed drawing will show a perfect young 
oak at the end of February, 1841, after having 
passed its first winter. The roots of the same are 
now (while we write) multiplied sixfold, and abound 
with glandular matter, from the part immediately 
below the acorn, and downward ; chiefl}^ at the points 
where the rootlets emerge. 
So far we have proof conclusive that water alone 
has nourished an oak during sixteen months ; every 
leaf was apparently perfect, and not one fell till the 
last autumn. Now the stem remains firm as that of 
any oak grown in loam. From the water, it might 
have absorbed a little carbonate of lime, and 
a trace of ammonia ; but where could it have 
derived substance — where was the humus^ the 
potassa — in fact, the nutrimental substances ^ 
usually insisted on as indispensable ? As to 
creation of parts ^ the onus prohandi rests with 
those who maintain the theory. 
IMPORTANCE OF SHORTENING THE SHOOTS OF EXOTIC 
PLANTS, WHILE IN A GROWING STATE. 
Happily for the progress of the human race, the prejudices of what are termed 
practical men are now rapidly yielding before the light of science, and the culti- 
vators of the soil are beginning to be aware that no effect of any kind can be 
produced with certainty, unless some knowledge be previously obtained of the 
actual process by which it is brought about. 
