Fkbrvajiy 1, 1901.] 



KNOWLEDGE. 



2o 



Founded by RICHARD A. PROCTOR. 



VoL.xxrv.] LONDON: FEBEUAEY 1, 1901. [No. 184. 



CONTENTS. 



Bv 



By 



Flowering Plants, with Illustrations from British 

 Wild-Flowers.— I. Roots and Stems. By E. Llotd 

 Pb.veof.e, b.a 



Living Millstones. By R. Ltdekker. (Illustrated) 



Mrs. Quickly's ''Table of Green Fields. ' By tlie Rev. 



D. B. FOTHERINGUAM, MA. (c.\NTAB.) 



Notes 



Constellation Studies.— II. The Region of Leo. 



E. Waltek Macxdeb, f.r.a.s. {Illustrated) 

 Constellation - Figures as Greek Coin • Types. 



Robebt Brown, Junr., r.s.A. 



Constellation Figures on Greek Coins. {^Plafe.) 



The Canals of Mars. By Miss M. A. Ohh. 



Letters : 



Gbaduai Change in oce Climate. By Alex. B. 

 MacDowall (Illustrated) 



Rainbow PHKyoMENA. By Paul A. Cobbold 



" Is HrsiAN Lipg Possible ojt othee Planets ': " By 



Thomas A. Wabino and Ahihue Ed. Mitchell .. 



Notices of Books 



Books Received ... 



British Ornithological Notes. Conducted tiy Habby V. 



WlTHEBBT, F.Z.S., M.B.O.r 



The Progress of Seismology during the Nineteenth 

 Century. By Cbaeles Datisox, sc.d., e.g. 9 



Microscopy. Conducted by M. I. Ceoss. {Illustrated) ... 



Notes on Comets and Meteors. ByW.F.DBNNiNo.F.a.A.s. 



The Face of the Sky for February. By A. Fowlee, p.e.a.s. 

 (Illuttra/ed) ■ ... 



Chess Column. Bv C. D. Locock, b.a 



25 



28 



31 

 32 



33 



35 



38 



3'J 



4(t 



40 

 41 

 43 



13 



41 

 45 

 46 



46 

 47 



FLOWERING PLANTS. 



WITH ILLUSTRATIONS FROM BRITISH WILD-FLOWERS. 



By K. Llovd Praegek, n.\. 

 I.— ROOTS AND STEMS. 



Wf. cannot take a country walk without being struck by 

 the variety of the vegetation which carpets the surface 

 of the g^und. Lowly as are nio.st, of our native plants 

 in comparison with those which clothe the hills and 

 valleys of tropical countries, we find notwithstanding 

 an infinite variety in the fonns assumed by their various 

 pai-ts, and we may note in our islands, as well as in a 

 Brazilian forest, the crowding, the stnaggling for room, 

 the waj' in which every nook, every coign of vantage, is 

 occupied by growing plants. Those species which arc best 

 adapted for the conditions afforded by any particular 

 situation and surroundings will achieve the most success 

 in life; will grow healthy and strong, increase at the 

 expense of their neighbours — for there is not room for 

 all — and will eventually produce the gi-eatest amount 

 of seed, to scatter abroad and carry on the race. To 

 achieve eventual success in this sti-ugglo for life, the 

 most important point is no doubt the adequate propa- 

 gation of the race ; but as this can only be obtained by 

 the success of the individual, it follows that every 

 feature, however slight, which tends to the efficacy of 

 the individual, is a distinct aid towards the success of 

 the race. 



The requirements of plants for the can-ying on of 

 life and growth are much the same as those which we 

 ourselves might demand — namely, a certain amount of 

 elbow-room, and of food and drink, light and heat. But 

 most plants being fixed to one spot, and not capable of 

 roaming at will, the conditions of their existence are 

 somewhat different from those of the majority of 

 animals. Their supply of water, and of most of the 

 inorganic and organic substances which they need for 

 the building-up of their- bodies, must be di-awn from the 

 soil, in which they fii-mly fasten themselves; while for 

 their supply of air and light they must largely depend 

 on their own exertions, that by growth they may offer 

 a sufficient surface to the aitmosphere and to the light 

 of day, and not allow their neighbours to unduly over- 

 shadow them. 



The function of the roots is twofold. They a.nchor 

 the plant finnly in its place, so that storm or rain may 

 not overtui-n it or can-y it away ; and they absorb froni 

 the soil, by means of minute hairs, the water needed in 

 the plant's economy, and dissolved in this water the soil 

 fiu-nishes the plant with various mineral .salts which 

 are needed for its growth. The roots of plants offer a 

 considerable vai-iety of form. Annual plants have 

 generally a much-branched root-system, not far-spread- 

 ing. Examine, for instance, the roots of the Goose-foots 

 or Oraches that on waste ground shoot up in a single 

 season into pyramidal masses of foliage and minute green 

 flowers, often three feet in height, only to perish with 

 the first frosts of winter. In plants such as these, the 

 rapid growth needs a continually increasing amount of 

 i-oot surface; this is acquired more easily by repeated 

 branching than by the lengthening of a main root. 

 Again, as the plant has not exi-sted continuously for 

 years on this particular spot, it has not already ex- 

 hausted the soil immediately suiTounding its root-iitock, 

 and in a limited area it finds nutriment sufficient for a 

 single year's growth. A third consideration is that this 

 elaborate structure of stems and leaves does not require 

 to be safeguarded again.st the stoi-ms of winter, for 



