INTRODUCTION. 
495 
hollow or pitcher-like nectaries (as in Helleborus), or they assume the most wonderful 
forms, like the petals of Aconitum^. 
Even before fertilisation, pollination is usually followed by striking changes in the 
parts of the flower, particularly in the gynaeceum, and especially when the parts con- 
cerned are delicate; thus the stigmas, style, and corolla wither, the ovary swells up 
(as in Gagea and Puschkinia), and the like. The most striking result of pollination 
is shown in many Orchideae, where the ovules are only formed as a consequence of this 
process. 
[The process of Fertilisation is essentially this, that protoplasmic and nuclear substance 
passes from the pollen-tube into the oosphere ; the protoplasmic substance coalesces 
with that of the oosphere, and the nuclear substance {male pronucleus) with that of the 
oosphere {female pronucleus) to form the definitive nucleus of the oospore.] 
Those changes however which are excited by fertilisation are still more energetic 
and varied than those which are consequent on pollination ; the oospore developes into 
the embryo; the endosperm — formed previously in Gymnosperms — is completed in Angio- 
sperms only subsequently to fertilisation ; the ovules grow along with the ovary, their 
layers of tissue are differentiated, become lignified, pulpy, dry, &c. The increase in size 
of the ovary, which is frequently enormous (in Cucurbita, Cocus, &c. several thousand 
times in volume), shows in a striking manner that the results of fertilisation extend 
to the rest of the plant, in so far as it affords the materials of nourishment. Striking 
changes in form, structure, and size take place after fertilisation, especially in the 
carpels, placentae, and seeds ; but very frequently similar changes result also in other 
parts. Thus, e.g., it is the receptacle that constitutes the fleshy swelling which is called 
the Strawberry, on the surface of which are seated the small true fruits; in the Mulberry 
it is the perianth of the flowers that swells up to form the succulent coating of the fruit ; 
in laxus it is a cup-shaped outgrowth of the axis beneath the ovule (the aril) that 
surrounds the naked seed with a red fleshy coating, &c. Popular usage includes under 
the term Fruit all those parts which exhibit a striking change as the result of ferti- 
lisation, especially when they separate as a whole from the rest of the plant; in ordinary 
language the Strawberry, as well as the seed of the Yew surrounded by its aril, the Fig, 
and the Mulberry, are all fruits. Botanical terminology limits the idea of Fruit within 
narrower boundaries, which, however, are not yet sharply defined. In the most exact 
use of botanical terms, the whole of the gynaeceum which ripens in consequence of 
fertilisation may be termed the Fruit. When the gynaeceum consists of coherent 
carpels or of an inferior ovary, the flower produces a single entire fruit ; if the carpels 
do not cohere, each forms a part of the fruit, or a fruitlet. This limitation of the term 
is often, however,, inconvenient ; and it would seem preferable to give it a definition 
which will vary in the diff"erent sections. 
The point to be most clearly borne in mind by the student is that the fruit is 
not a new plant-structure. All the parts of the fruit which are morphologically 
determinable, originate and assume their morphological character before fertilisation ; 
the result of fertilisation is merely a physiological change in the parts. The only new 
parts in a morphological sense are the embryo and the endosperm, which are pro- 
duced in the ovule. 
The Inflorescence, When a shoot which has previously formed a large number of 
foliage-leaves terminates in a flower, the flower is said to be termijial ; if, on the other 
hand, a lateral shoot developes at once into a flower, with one or at most a few bracteoles 
beneath it, the flower is termed lateral. Sometimes the first primary axis which proceeds 
from the embryo terminates in a flower ; but more often the axis continues to grow, 
or its growth comes to an end, without forming a flower, and it is only lateral shoots of 
the first, second, or a higher order that terminate in flowers. In the first case the 
^ [On this subject see Müller, Befruchtung der Blumen durch Insekten, 1873 ; and Sir John 
Lubbock, British Wild Flowers in relation to Insects ; also Book III. of this work.] 
