DISPERSAL BY ANIMALS. 865 



The phenomenon in question also enables us to interpret the meaning of the 

 changes undergone by fleshy fruits at the season when theii^ dispersion becomes 

 desirable, inasmuch as they serve the purpose of attracting animals, and the same 

 consideration applies to the contrivances whereby animals are discouraged from 

 taking the fruits before they are ripe. Mention has already been made of these 

 latter contrivances on p. 444; and as regards the attraction of animals with a view 

 to the dispersion of ripe fruits the following particulars are of especial interest: 

 Fruits and seeds that are still unripe are hidden amongst the leaves of the mother- 

 plant, have a green eoloiu- resembling that of the foliage, and are destitute of scent. 

 On ripening the fruits are exposed, the coats of the fruits acquire a conspicuous 

 coloration, and frequently emit a strong scent. In the cases where the seeds alone 

 are dispersed and the pericarps are left behind, as, for instance, in Pceonia Russi, 

 Euonymus vei^ucosus and Magnolia grandifiora, the capsules or follicles burst 

 open, and the seeds are of a bright red or yellow colour, sometimes flecked with steel- 

 blue and black, which renders them visible from afar. In the above-named species 

 of Euonymus and Magnolia they emerge from the pericarps and hang at the ends 

 of threads which rendei's them even more conspicuous. The particular colour assumed 

 by fruits and seeds at the time of maturity varies according to that of the foliage 

 by which they are surrounded. The difierent tones of red stand out best from a 

 green environment; therefore, for plants with evergreen foliage (e.g. Ardisia, 

 Gaidtena, Ilex, Taxus, Arbutus Unedo, Arctostaphylos uva-ursi, Vacciniutn 

 Vitis-Idcea) a red coloration is the most advantageous. Also in the case of plants 

 with foliage which, although not evergreen, does not acquire an autumnal tint at the 

 season when the fruits are ripe, e.g. the Strawberry, the Raspberry, the Currant, 

 the Wild Cherry, and the Red-berried Elder (Sambucus Ebulus) the red hue of the 

 fruits is of great value. On the other hand, red fruits would stand out but Little 

 against a background of foliage that had already donned the red or yellow tints 

 of autumn by the time they ripened, and accordingly the fi'uits of Ampelopsis 

 hederacea, Camus sanguinea, Prunus Padus, Arctostaphylos alpina, Vaccinium, 

 Myrtillus and V. uliginosum,, &e., are, as a fact, blue or black. Sometimes the 

 fruits are black and the fruit-stalks red, as in Sambucus nigra, or the fruits are only 

 coloured on the side exposed to view, as in the Apple and the Pear. The fruits of 

 the Quince and the Pine-apple are set off by their yellow colour from the blue-green 

 foliage. White berries, such as those of Cwnus alba and SympJioricarpv^, occur 

 principally in plants which cast their leaves before the fi'uit is ripe. Standing out 

 against the brown or gray background formed by the leafless branches and the 

 fallen leaves of late autumn these white fruits are clearly visible. The extent to 

 which fruits are advertised by their scents is a matter of common experience, and 

 we need only refer for illustration to the Strawberry, the Raspberry, the Quince, and 

 the Pine-apple. 



Seeing that the seeds and stones containing seeds of the fleshy fruits eaten by 

 thrushes and blackbirds only remain a short time in the crop and intestine of the 



bird, it is probable that the plants in question are disseminated by this agency to 

 Vol. II. 105 



