404 



NA TURE 



[August 25, 1898 



The moths which issue from these larvae are captured in great 

 numbers by Sunday ramblers, who resort to the l)ase contriv- 

 ance of bringing a female moth in a cage. The self-styled 

 " naturalist " sits on a rock, and captures one by one the eager 

 moths which come about him, afterwards pinning out the 

 expanded wings to form grotesque patterns, or selling his speci- 

 mens to the dealers. Certain wide-spread Diptera are plentiful, 

 and there are a few which pass their larval stages in the quick- 

 running streams which flow down from the moor. The small 

 number of good-sized insects partly explains (or is explained by) 

 the paucity of conspicuous scented or honey-bearing flowers. In 

 this the moor contrasts strongly with the higher Alps. Bees, 

 however, get much honey from the large-flowered heaths and 

 ling ; heather-honey is considered better than any other. A 

 little scale insect (Orthesia uva) has been found plentifully on 

 the Sphagnum of the moors, particularly in Cumberland. ^ A 

 big spider {Epeira diadema) spreads its snare among the 

 heather, and may now and then be seen to deal in a particularly 

 artful fashion with a wasp or other large insect which may have 

 blundered into the web. The spider cuts the threads away till 

 the struggling insect dangles ; cautiously on outstretched leg 

 holds out and attaches a new thread, and then sets the wasp 

 spinning. The silken thread, paid out from the spinneret, soon 

 . binds the victim into a helpless mummy.-' I have never found 

 gossamer so abundant as on the verges of the moor. 



In our day the Yorkshire moor harbours no quadrupeds, and 

 the grassy hills none but small quadrupeds. It was not always 

 SI). At Raygill, a few miles from us across the moors, a collec- 

 tion of bones was discovered a few years ago in quarrying. A 

 deep fissure in the rock had been choked ages before with stones 

 and clay. This fissure was cut across by the working face of 

 the quarry. Many bones were brought out of it, bones of the 

 ox and roebuck among the rest. But mixed up with these were 

 teeth and bones of quadrupeds now altogether extinct or no 

 longer found in Britain, such as the straight-tusked elephant 

 {E. antiquus), the hippopotamus, a southern rhinoceros {R. 

 leptorhimis), the cave hyaena, and the European bison. The Irish 

 elk is often dug up in Yorkshire, the reindeer and the true elk 

 now and then. Not very long ago these and other large 

 quadrupeds grazed or hunted a country which can now show no 

 quadruped bigger than a fox. 



It is evident that the moors, valleys and plains of Yorkshire 

 have been depopulated in comparatively recent times. The dis- 

 appearance of so many conspicuous species is commonly 

 attributed to the glacial period, but I think that the action of 

 man has been still more influential. The extinct animals are 

 such as man hunts for profit or for his own safety. Many of 

 them, among others the cave-bear, Machairodus, Irish elk, 

 mammoth, and straight- tusked elephant, are known to have 

 lasted into the human period. That so many of them were last 

 seen in the company of man is some proof that he was concerned 

 in their death. 



Central Europe, before man appeared within its borders, or 

 while men were still few, little resembled the Europe which we 

 Kno\y. Much of it was covered with woods, morasses or wastes, 

 and inhabited by animals and plants, of which some ranged into 

 the Arctic circle, others to the Mediterranean, Africa and India. 

 The worst lands of all— cold, wet, and wind-swept— had doubt- 

 less then, as now, the greatest proportion of Arctic species. But 

 it is likely that the passage from the bleak hills to the more 

 fertile valleys and plains was not then su abrupt as at present. 

 All was alike undrained and unenclosed ; and what we know of 

 the distribution ot life in Pleistocene Europe shows us that a 

 large proportion of our European animals and plants are not 

 restricted by nature within narrow limits of latitude or climate. 

 Species which are now isolated, at least in Central Europe, 

 occupying moors or other special tracts, and surrounded by a 

 population with which they have little in common, were formerly 

 continuous over vast areas. In the early days of man in Europe 

 many plants, birds, and quadrupeds which are now almost 

 xclusively Arctic may well have ranged over nearly the whole 

 of Europe. 



As men gradually rooted themselves in what are now the 

 most populous countries of the world, the fauna and flora under- 

 went sweeping changes. The forests were cleared, and trees of 

 Imported species planted here and there. The land was drained, 

 and fenced, and tilled. During the long attack of man upon 



^Jf^J'Z'^^}'^^' q"°'ed by R. Blanchard in Ann. Soc. Eni. Fr., torn. Ixv. 

 p. 681 (1896). 



2 Blackwall's " Spiders," vol. ii. p 359. 



NO. 1504, VOL. 58] 



wild nature many quadrupeds, a few birds, some insects, and 

 some plants are known to have perished altogether. Others 

 have probably disappeared without notice. Certain large and 

 formidable quadrupeds, though they still survive, are no longer 

 found in Europe, but only in the deserts of the south or the un- 

 peopled northern wastes. Thus the lion, which within the 

 historic period ranged over Greece and Syria, and the grizzly 

 bear, which was once an inhabitant of Yorkshire, have dis- 

 appeared from every part of Europe. Tillage and fencing have 

 checked the .seasonal migrations of the reindeer and the lemming. 

 Useful animals have been imported, chiefly from the south or 

 from Asia. Useful plants have been introduced from ancient 

 centres of civilisation, and common farm-weeds have managed 

 to come in along with them. Many species of both kinds are 

 southern, many eastern, none are Arctic. In our day the 

 cultivated lands of Europe are largely occupied by southern or 

 eastern forms, and the wastes appear by contrast with the im- 

 ported population more Arctic than they really are. Even the 

 wastes are shrinking visibly. The fens are nearly gone, and we 

 shall soon have only a few scattered moors left to show what 

 sort of vegetation covered a great part of Europe in the days of 

 choked rivers and unfenced land. The moors themselves 

 cannot resist the determined attack of civilised man. Thousands 

 of acres which used to grow heather are now pastures or 

 meadows. 



What we call the Arctic fauna and flora of to-day is apparently 

 only the remnant of an assemblage of species varying in hardi- 

 ness, which once extended from the Arctic circle almost to the 

 Mediterranean. If climate and soil alone entered into the 

 question, it is likely that the so-called Arctic fauna and flora 

 might still maintain itself in many parts of Central Europe. 

 This Arctic (or ancient European) flora includes many plants 

 which are capable of withstanding extreme physical conditions. 

 Some thrive both on peat and on sand, in bogs and on loose 

 gravel. They may range from sea-level to a height of several 

 thousand feet. They can endure a summer glare which blisters 

 the skin, and also the sharpest cold known upon this planet. 

 Some can subsist on soil which contains no ordinary ingredient 

 of plant-food in appreciable quantity. Such plants survive in 

 particular places, even in Britain, less because of peculiarly 

 appropriate surroundings, or of anything which the microscope 

 reveals, than because they can live where other plants perish. 

 Ling, crowberry, and the rest are like the Eskimo, who dwell 

 in the far north, not because they choose cold and hunger and 

 gloom, but because there only can they escape the competition 

 of more gifted races. The last defences of the old flora are 

 now being broken down ; it is slowly giving way to the social 

 grasses, the weeds of commerce, and the broad-leaved herbs of 

 the meadow, pasture, and hedge-row. The scale has been turned, 

 as I think, not so much by climatic or geographical changes, as 

 by the acts of man. 



Every lover of the moors would be glad to know that they 

 bid fair to be handed down to our children and our children's 

 children without diminution or impoverishment. The reclaiming 

 of the moors is now checked, though not arrested, and some 

 large tracts are reserved as open spaces. But the impoverish- 

 ment of the moors goes on apace. The gamekeeper's gun 

 destroys much. Enemies yet more deadly are the collectors 

 who call themselves naturalists, and the dealers who serve them. 

 A botanical exchange club has lately exterminated the yellow 

 Gagea, which used to grow within a mile of my house. When- 

 ever a kingfisher shows itself, young men come from the towns ' 

 eager to slay it in the name of science. No knowledge worth 

 having is brought to us by such naturalists as these ; their collect- 

 ing means mere destruction, or at most the compilation of some 

 dismal list. If the selfish love of possessing takes hold of any 

 man, let him gratify it by collecting postage-stamps, and not 

 make hay of our plants and mummies of our animals. The 

 naturalist should aspire to study live nature, and should make 

 it his boast that he leaves as much behind him as he found. 



THE MARINE FA UNA IN LAKE TANGANYIKA. 

 AND THE ADVISABILITY OF FURTHER 

 EXPLORATION IN THE GREAT AFRICAN 

 LAKES. 

 'T'HERE is a story which redounds to the sagacity of a certain 

 Dutch farmer, who, on the sudden appearance of herrings 

 in the ditches on his property, sold it, on account of the indis- 

 putable evidence which such fish afl"orded, of the leaky con- 

 dition of the dykes. The Dutchman's inference will serve to 



