INTRODUCTION TO BOTANY. Xxvli 
only increase of size of the whole plant or of particular parts, but in- 
crease of number, or branches, or leaves, or leaflets of a compound leaf ; 
or it may diminish the hairiness of the plant or induce thorns to grow 
out into branches, &e. 
Capsules which, while growing, lie upon or close to the ground, will often 
become larger, more succulent, and less readily dehiscent, than those 
which are not so exposed to the moisture of the soil. 
Herbs eaten down by sheep or cattle, or crushed under foot, or burnt over, or 
otherwise checked in their growth, or trees or shrubs cut down to the 
ground, if then exposed to favourable circumstances of soil and climate, 
will send up luxuriant side-shoots, often so different in the form of their 
leaves, in their ramification and inflorescence, as to be scarcely recogni- 
zable for the same species. 
Annuals which have germinated in spring and flowered without check, will 
often be very different in aspect from individuals of the same species, 
which, having germinated later, are stopped by summer droughis or the 
approach of winter, and only flower the foll ee Senet ae = 
growth. ‘The latter have often been mistaken for 
Hybrids, or crosses between two species, come under the category of anoma- 
lies from a known cause. Frequent as they are in gardens, where they 
are artificially produced, they are probably rare in nature. Absolute 
proof of the origin of a plant found wild is of course impossible ; but it 
is pretty generally agreed that the following particulars must always co- 
exist in a wild hybrid. It partakes of the characters of its two parents ; 
it is to be found isolated, or almost isolated, in places where the two 
parents are abundant ; if there are two or three, they will generally be 
dissimilar from each other, one partaking more of one parent, another 
of the other ; it seldom ripens good seed ; it will never be found where 
one of the parents grows alone. Where two supposed species grow toge- 
ther, intermixed with numerous intermediates bearing good seed, and — 
passing more or less gradually from the one to the other, it may gene- 
rally be concluded that the whole are mere varieties of one species. The 
beginner, however, must be very cautious not to set down a specimen as 
intermediate between two species, because it appears to be so in some, — 
even the most striking characters, such as stature and foliage. Extreme 
varieties of one species are connected together by transitions in all their 
characters, but these iia pgrhecigristemtt roe agp 
cimen. The observation of a single intermediate is, therefore, of little 
value, unless it be one link in a long series of intermediate forms, and, 
when met with, should lead to the search for other connecting links. = 
2. Accidental aberrations from the ordinary type, —- those of which the 
cause is unknown. i S 
These require the more attention, as they may ometi the beginner 
whilst aberrations above 
far astray in his search for the genus, — gprs os inti ion of 
rednosd mine 06 1 
se eee ed SG aver cocasionally with 
be found, even in in. a wild sinis; with double flowers, that is, with 
ony ay be oa, of petals 
Plants which have usually conspicuous petals will occasionally appear without 
petals, either to the flowers produced at particular seasons, or to all the 
flowers of particular plants; or the petals may be reduced to narrow 
slips, or variously cut. 
Flowers usually very irregular (81) may, on certain individuals, lose more or 
less of their irregularity. Spurs may disappear, or be produced on all, 
instead of only one of the petals. 
One part may be occasionally added to or subtracted from the usual number 
of TS more — in serene peer ie 
