8 
JUVENILE LEAVES. 
not suspect any kinship between the two plants. Where the leaves of the seedling 
were stalkless or sessile and opposite we may find those of the adult tree= long- 
stalked and attached alternately to the twig; where the seedling earned short and 
broad leaves we may find the adult tree carrying leaves that are long and nanow , 
where the veins in the leaves of the seedling were wide apart we may find those in 
the leaves of the adult tree near together. Quite frequently the juvenile and adult 
forms of leaf will be found on the same tree even after it is mature enough to bear 
fruit; and occasionally flowers and fruits will he seen on a twig that still carries 
juvenile leaves. A few species continue to produce the sessile opposite form of 
leaf throughout their lives, thereby, as is supposed by some authorities, represen - 
ing the ancestral type of the genus. Sessile or stalkless leaves are nearly always 
found in opposite pairs; but there are one or two species m which they are 
alternately arranged. 
t ptt/rc ^TITTUP-SPROUTS. 
Many trees have the capacity to produce leaf buds in two different ways. 
The ordinary way is to produce them in the axils of already developing leaves; 
but belonging to several genera are trees that, under special stimulus, can give 
birth to new buds from parts of the cambium tissue where there are no leaves. 
These latter are called adventitious buds. Certain elms and poplars, some wattles, 
and a good many other trees can form buds and throw up suckers along their 
lateral roots. Unless in very rare and exceptional cases, eucalypts never do this, 
but, like oaks, they are endowed with wonderful power to make new growth from 
any part of the stem or branches that may have been cut back or mutilated 1 he 
foliage borne by the sprouts that thus break out just below the cut or mutilation 
is at first and for some time closely similar to that of the seedling. It is a case 
of reversion to the seedling form caused in some way by the injury to the tree; 
and in the absence of seedlings young stump-sprouts will serve almost equally 
well for purposes of specific determination. Stump-sprouts are often called suck¬ 
ers, and their leaves sucker leaves. 
Nature is much greater and much more complex than any human language. 
Hence science is constantly finding difficulty in expressing and lecoiding its dis¬ 
coveries. J. H. Maiden and others call the leaves of seedlings and stump-sprouts 
“juvenile leaves” and the leaves of adult trees “mature leaves”. R. T. Baker 
applies to the former the word “abnormal” and to the latter the word “normal”. 
In both cases the language used may possibly be misunderstood; for in truth the 
leaves of a seedling or of a stump-sprout when fully grown are just as mature and 
just as normal as the leaves of any older tree. They are mature and normal for the 
plant in the juvenile stage of its life. It is nature’s norma or rule for certain 
eucalypts that they shall produce leaves of one form when they are young or when 
they have been mutilated and leaves of another form when they are older and 
have not been mutilated. The truth will perhaps be expressed with least ambi¬ 
guity if we simply write and speak of the two forms as (a) Juvenile leaves, 
including leaves of seedlings and stump-sprouts; and ( b ) Adult tree leaves, or 
leaves of the adult tree. 
LEAVES OF SAPLINGS. 
When our trees have passed the seedling stage but have not yet become fully 
mature we call them saplings. Eucalyptus saplings often exhibit both juvenile 
and adult characters. In favourable conditions they are usually very vigorous and 
