Oct. 2C, 1883.] 



• KNOWLEDGE ♦ 



251 



^^ MAGAZINE OF SCIENCE 



PLAINLYVfORDED -EXACTLY DESCRIBED 



LONDON : FRIDAY, OCT. 26, 1883. 



Contents op No. 104. 



FAGB 

 A Naturaliet's Year. Chestnuts 



Fall. liv Grant Allen 251 



.How to Oct Strong 252 



The Chemistry of Cookery. XXI. 



Bt W. Mattieu WilUams 263 



The Morality of Happiness. By 



Thomas Poster 251 



The Fisheries EiUibition. VIII. ' 



By John Ernest Ady 355 



The Sun*8 Distance. By Professor 



E. S. Ball, LL.D 257 | 



PAGE 



Nights with a Three-Inch Tele- 

 scope, (lllui.) 258 



Sea Anemones. VII —The Para- 

 site. (Itlua.) By T. Kimber ... 259 



Trifvcles in I8;3 21)0 



The Face of the Sky. By F.E. A.S. 261 

 Correspondence ; The Barn Uwl — 

 Palaeolithic Man — Property of 



Numbers, ic .' 261 



Our Whist Column 265 



Our Chess Column 266 



A NATURALIST'S YEAR. 



By Grant Allen. 



CHESTNUTS FALL. 



ON thewootled slope where the park shelves slowly toward.? 

 the Bourne Brook, the ground today is thickly 

 strewn in many places with the sharp prickly liusks and 

 small, barren, angular nutlets of the beautiful Spanish 

 chestnuts. They are not truly indigenous to Britain, these 

 noble spreading forest trees, though they have been planted 

 so long in our pleasure-grounds and lawns that we have 

 got to look upon them almost as naturalised British sub- 

 jects ; and the climate, though it suits the leaves and wood 

 well enough, i.s not sufficiently kindly to ripen the fruits in 

 due season; tliey are almost always mere empty, shrivelled 

 shells here in England, so that we have to import seed for 

 sowing from the mountain regions of southern Europe. 

 There we have all seen them growing in their own wild 

 luxuriance on the lower escarpments of the Alps or 

 the Apennines, and bringing forth fertile nuts suffi- 

 cient to feed lialf the teeming population of the Lombard 

 plain in seasons of scarcity. Side by side with them in 

 the park here, the boys are impartially sliying sticks at 

 the very similar, though wholly unrelated, clusters of the 

 common horse-chestnuts, which, in spite of their close e.x- 

 ternal likeness, belong in reality to a totally different and 

 much more restricted family. The true chestnut is a catkin 

 bearer, a near relation of tlie British oak, as one might 

 almost guess at siglit from its foliage and habit : the horse- 

 chestnut is a luember of a tribe unrepresented in our native 

 English flora, but not very unlike the maples and syca- 

 mores in its principal characters. It is interesting to note 

 how in the case of tlie.se two wholly different and originally 

 dissimilar trees similarity of circumstances has at last pro- 

 duced such great similarity of adaptive peculiarities. 



The key to this strange resemblance between the chest- 

 nut and the horse-chestnut is to be found in the fact that 

 they art! both hk/s — they havt; survived in the struggle for 

 existence by adopting for their seed-vessels the exactly 

 opposite tactics from those adopted by tlie true fruits. A 

 fruit, as we have often seen, is a seed-vessel which lays 

 itself out, by all the allurements of bright colour, sweet 

 scent, sugary juices, and nutriti\e properties, to attract 



animals who will aid it by swallowing it, and so eventually 

 dispersing its seeds. But a nut is a seed-vessel which, on 

 the contrary, being richly stored with starches and oils 

 for the supply of the young plantlet, would be injured and 

 diverted from its real intent and purport if it were to be 

 eaten and digested by any animal. Accordingly, nuts have 

 concentrated all their efforts upon repelling rather than 

 upon attracting the attention of animals ; or, to put it in a 

 more strictly physical way, those nuts which have happened 

 to bo least attractive in colour and most protected by hairs, 

 spines, prickles, or bitter juices have best succeeded in 

 escaping the attacks of animals, and so have prospered best 

 in the struggle for existence. Thus, to drop into metaphor 

 once more, while the fruit wants to be eaten, the nut, on 

 the contrary, wants to escape. 



We may take the chestnut as a very good example of 

 the general result which the necessity for protection 

 usually produces in these peculiar seed-vessels. While it 

 still grows on the tree the entire fruit is green and unob- 

 trusive, hardly noticealjle at a little distance among the 

 heavy foliage which covers it on every side. Compare this 

 shrinking and secretive habit with the brilliancy and 

 vividness of oranges and mangoes, or even of our own 

 bright-coloured northern rose-hips, and haws, and mountain 

 ashes, and holly-berries. Again, instead of being smooth- 

 skinned and soft, like these bird-enticing fruits, the outer 

 rind of the chestnut is rough and repellent with serried 

 prickles, which rudely wound the tender nose of the 

 too-inquisitive squirrel, or even the feathery cheeks of the 

 more protected nut-hatch. Once more, when the separate 

 nuts inside have fallen out upon the ground, they are no 

 longer green like the foliage on the tree, but light brown 

 or " chestnut," like the dead leaves and withered bracken 

 into whose midst they have gently fallen. Chestnuts 

 themselves are apparently sufficiently protected by these 

 devices of colour and prickliness ; they do not seem further 

 to require the sjjecial nut-like covering of a hard and 

 woody shell ; but the filbert, which suffers far more from 

 the depredations of dormice, squirrels, nuthatches, and 

 other birds or mammals, has not only encased itself without 

 in a green husk covered by sharp and annoying little hairs, 

 but has also acquired a very solid and difficult shell, which 

 often succeeds in baffling even the keen teeth and beaks of 

 its persistent and aggressive animal foes. 



Indeed, even among British nuts, one may trace a 

 regular gradation (not, of course, genealogical) from the 

 softest and least-protected to the hardest and most defensive 

 kinds. The acorn, produced in vast numbers by a very 

 large and long-lived tree, the oak, has hardly any need of 

 a strong outer coat of armour, especially as its kernel is 

 rather bitter and far from attractive to most animals, 

 though it still feeds a considerable legion of lioarding 

 squirrels, and must once have been munched in immense 

 quantities liy the native wild boars, or their mediaval suc- 

 cessors, the half-tamed forest swine. In the beech, the shell 

 of the actual nut itself is merely leathery ; but the outer 

 coat cr involucre is sprinkled over with distinctly protec- 

 tive prickles. (It is worth while to note in passing that 

 the beechnuts or mast rarely contain a kernel in Britain — 

 in other words, they are almost always sterile ; wliereas in 

 other countries wliere the beeclies are more sturdy, the 

 nuts are usually fertile ; and this fact may be put side by 

 side with the correlative fact that the beecli is a decadent 

 tree in England, where it was once dominant, but is now 

 rapidly dying out before our very eyes, at least in its 

 indigenous form.) In the lime, the very smidl nut has a 

 decided shell, wliile its globular shape also makes it 

 ditlicult for quadrupeds to open with their paws and teeth. 

 Finally, in the hazel, the filbert has a very hard integument 



