July 1, 1891.] 



KNOWLEDGE. 



131 



are hidden. Hence the rosy cheek of the apple, peach, &c. 

 In the magnoHa we find a remarkable arrangement. Its 

 fruit is dry and contains but one seed. One-seeded fruits 

 do not as a rule open, but themselves become detached 

 from the mother plant, and are dispersed. Magnolia is, 

 however, an exception. Itstme-seeded fruit which remains 

 on the branch opens suddenly, and the seed is jerked out ; 

 l)nt, instead of falling to the ground, the seed is retained 

 by its long string-like stalk or funiculus, and hangs down 

 outside the capsule. The external portion of the seed 

 is succulent and coloured, resembling that of the pome- 

 granate, and there can therefore be no doubt that the 

 object of thus hanging out the seed is to expose it in 

 such a way that it will readily catch the eye of some bird. 



A peculiarity noticed in the raspberry and some others 

 is deserving of mention. The fruit, partially hidden by 

 the leaves, can be seen more readily by a person standing 

 at some distance from the bush than when close beside it. 

 The intention seems to be to discourage birds from settling 

 on the plant and devouring its fruits in quantity on the 

 spot. This peculiarity compels a bird to make more 

 numerous journeys, and secures wider distribution. Further, 

 when the bird is imder the necessity of flying to a neigh- 

 bouring tree to consume the fruit it has got, or to make a 

 survey in search of more, the seeds stand a better chance 

 of being delivered in localities favourable to their develop- 

 ment — that is, in situations where birds are in the habit 

 of perching, such as thickets and shaded plantations 

 corresponding to the habitat of the rasp and similar 

 plants. Wind-carried seeds would have very little chance 

 of penetrating these sheltered situations unless of minute 

 size. But the smaller the size of a seed the more scanty 

 is the stock of nourishment it can afford for the develoiJ- 

 ment of the embryo during germination. This, to plants 

 which aft'ect a shady habitat, would be a decided disad- 

 vantage, and therefore the mass of the seed cannot with 

 safety be reduced below a certain limit. 



Succulent coloured fruits are very common in the order 

 Hosaceie, to which most of our cultivated fruit-trees belong. 

 The apple, pear, medlar, quince, peach, plum, cherry, rasp, 

 and strawberry are members of this order. It is some- 

 what remarkable that while the fruits of Rosacea; are thus 

 highly specialised the flowers should belong to a com- 

 paratively simple type, having, as a rule, separate petals 

 and exposed honey. In some genera, svxch as Alclifinillu 

 and I'litcviuiii, the flowers appear to have degenerated into 

 the apetalous condition. 



Glancing over the list of plants which produce succulent 

 fruits, we observe that these are either trees or shrubs, 

 herbaceous species being almost unrepresented. The same 

 rule evidently applies to fruits which, as we have seen, 

 holds good in the case of flowers requiring the assistance 

 of birds. Fruits of this description produced too near the 

 ground would not only escape the notice of birds but would 

 present a strong temptation to many terrestrial creatm-es, 

 and attract a host of enemies in no way fltted to help in 

 dissemination. Of this we have convincing evidence in 

 ' the frequc'ncy with which cultivated strawberries are 

 devoured by snails. Like large mellifluous flowers, fruits 

 adapte<l to birds require to be placed at some distance from 

 the ground, beyond the reach of snails, larva-, ants, rodents 

 and larger quadrupeds. The prickles and hairs on the 

 stalks and outsides of many flowers are believed to prevent 

 small creeping insects from reaching the nectar. Many of 

 thest! structures may, however, render more important 

 service in defending the fruit ; the prickles of the rasp and 

 bramble would appear to be of use in protecting the fruit 

 quite as much as the flowers and foliage. 



Birds in eating succulent fruits may either reject the 



stones and seeds, or these may be swallowed and pass 

 through the intestines of the bird without losing their 

 germinating power. This ordeal would even seem to 

 benefit some seeds by facilitating their germination. It 

 has at least been asserted, on reliable authorit}-, that nut- 

 megs which are swallowed by pigeons for the sake of the 

 mace, thrive much better if dropped by the birds than 

 when planted by man. Succulent fruits commonly have 

 seeds so hard that they resist the action of the mandibles, 

 gizzard, and stomach of most birds. In drupaceous fruits 

 the seed itself is not hard, but it is enclosed for protection 

 in a woody endoearp or stone. The pomegranate has the 

 testa or outer layer of the seed soft, but the central core is 

 woody ; in any case the part ultimately dispersed by the 

 birds is hard. This, in the date and grape, is the seed ;' 

 in the strawberry and flg, the fruit or achene ; in the 

 cherry, rasp and bramble, the endoearp ; and in the goose- 

 berry and currant, the indurated core of the seed. 

 Indurated seeds and fruits are not, however, confined to 

 plants which employ birds in the work of dissemination. 

 Mice, squirrels, and other small rodents, consume large 

 numbers of seeds, and where this danger has to be met it 

 is of the highest importance to a plant to possess hard 

 seeds. This is in all probability the explanation of the 

 remarkably hard nutlets of some of the Labiatie and 

 Boraginaceie, and of the stone-like seeds called Brazil nuts. 

 The flinty cocci of Lit/iosjiiriiiiiiii are calculated to give 

 even a rodent the toothache. The glassy grains of Coir 

 larrijmd, known as .lob's tears and used as beads, and the 

 horny albumen of the palm I'ht/tclt'iis iiuicrocdrjKi, which 

 furnishes vegetable ivory, are marked examples of this 

 excessive hardness. 



By accidentally dropping nuts, monkeys and squirrels 

 may occasionally assist in dispersion ; but it may be doubted 

 whether this occasional service is a sufficient compensa- 

 tion for the quantities they consume. The nuts them- 

 selves, at least, cannot be said to possess any special 

 provision for this mode of dispersion. The strong beaks 

 of the parrot tribe, on the other hand, are well adapted for 

 breaking open hard-shelled fruits of this description. 



A disagreeable taste will prevent a seed being eaten by 

 animals or swallowed along with the sweet pulp of the 

 fruit. Such is apparently the meaning of the bitterness 

 of the orange seeds, of one variety of almond, and of the 

 fresh spermoderm of the walnut. ( 'uirtihts imliciis, some- 

 times used to give bitterness to malt liquors, is the fruit 

 of a plant belonging to the Menispcrmaceie. The seeds 

 of fox-glove and mullein are bitter, and those of the 

 upas tree intensely so. In other cases the seed has a hot, 

 pungent taste, as in the mustard and other crucifers. 

 Pepper is obtained from the fruits of various orders ; 

 black pepper from Pi'iicr iiifiruiii (Piperacea') ; .Jamaica 

 pepper from Hiii/oiiii intin'ntu, a plant of the myrtle family ; 

 Cayenne pepper, chillies, bird-pepper and cardamons fi'om 

 various members of the Solauaceae. From Xi;ii'lla .tutira 

 (Ranunculacea-), Tasmanniii oromatint (Magnoliaceff), 

 Xijloiiia ardiiiiiticii (Anonacca-), from the Elatinaceus or 

 water-peppers, some of the \'erbenas, the Polygouacea' 

 (I'oli/i/oiKiiii lii/ilrojii]i,r). and from some plants of the 

 ginger order, pungent or peppery seeds are obtained. 



The fruits of the guelder rose, honeysuckle, ivy, dog- 

 mercury, lobelia, and of some of the fox-glove order 

 possess emetic properties, so that in the event of the seeds 

 being swallowed there is a possibility of their being vomited 

 up again. The robin eats the berries of honeysuckle, 

 but vomits them afterwards. The fig and tamarind are 

 examples of laxative fruits, a quality shared to a greater or 

 less degree by most of the succulent class. Many, indeed, 

 are powerful purgatives, such as the colocyuth [i itnillu^ 



