Dec. -23, 1881.] 



♦ KNOWLEDGE 



167 



THE OEIGIN OF BUTTERCUPS. 



117] — I am sure tliat most of our readers could not fiiil but 



iL-e the clear and highly descriptive article upon " The Origin of 



torcups," a valuable treatise upon a botanical snbject. without 



: anical technicalities, and rendered in such a manner that even 



ti.e least unscientific person reading the article would have his 



knowledfre considerably extended respecting buttercups. 



1 cannot, however, understand Mr. Grant Allen's theory of evolu- 

 :; re.«(iectiug cut leaves. Ue says, " As a rule, just in proportion 

 vegetation is thick and matted, do the plants of which it is com- 

 - d tend to dcvelope minutely divided and attcnaated foliage." I 

 i that the rule is the very reverse, for iu traversing any waste 

 L> of land where the struggle for existence is left to itself, one 

 ^ the very plants that predominate are those with entire leaves, 

 . grasses, daisies, primroses, docks, ic, &c., and hold their o\vn 

 - Liiist the finely-cut leaved species; indeed, one scarcely sees the 

 :ercnp with its cut leaves growing in any prof usion on uncul- 

 tivated ground. 



It is only in protected meadows that it flourishes in abundance ; 



"ivliereas the farmer carefully uproots those having entire leaves, 



:, 'wing well that under their broad leaves no grass will grow. 



Tliose plants having cut leaves are, as a rule, "tall growers," 



1 have a weak and slender stem compared with the height of 



t ■.<• plant. Have not these developed cut leaves in order that the 



v.;iul may not break them'down, but allow it to pass freely through? 



I :'. on the contrary, they had to dcvelope entire leaves, they would 



at a disadvantage in even an ordinary breeze. Upon the same 



uciple many tall plants have entire leaves, but as they approach 



top of the stem, the leaves are invariably smaller. Conse- 



titly, where the plant is weakest the leaves .are smallest. 



A -rain, many [plants having entire leaves throw up a flowering 



.1 entirely devoid of leaves, probably learning by experience 



.at if they had to produce leaves there, snap would go their stems 



— viz., plantain, foxglove, hyacinth, grasses, ic. 



U maybe argued that few of ottr large forest trees have cut 



ves, and that, therefore, my theoiy respecting the wind would 



But I hold that they possess advantages equal to cut leaves 



.aWng their blades placed at the end of petioles, and articulated 



the stem, so that they may bend and allow the wind to pass 



:;out injuring the tree. I hold that petioled leaves are merely a 



Iilication of cut leaves. Few of our radical leaved plants 



I j'ussess petioles to their leaves, not being required for such a 



I "lowly" position. West Riding. 



BEES AS FLOWER FERTILISERS. 



[1-18] — In the suggestive article by Mr. Grant Allen iu K.NOW- 

 LEDGE Xo. 4, on the " Origin of Buttercups," an error has crept in 

 with regard to bees. I am a bee-keeper on a somewhat large scale, 

 and, consequently, interested iu knowing from what flowers bees 

 make their collections ; but, though we have abundance of butter- 

 cups here, the hive bees do not visit them. Certainly buttercups 

 are not included by bee-keepers among honey plants. 



I do not, however, take exception to the assertions of scientiiic 

 men, that bees are important aids in the cross fertilisation of 

 flowers. When I say that the nnmber of good honey-producing 

 plants are comparatively few, and bees select the best yielders 

 for the time being, I mean the probabilities appear to me to be 

 verj- much against flowers being dependent upon bees for the fer- 

 tility of their seeds. 



Another circumstance is worth notice. When hive bees make 

 collections of pollen from osiers, they fly straight to and from the 

 tree, without passing from the male to the female flowers, a fact 

 which may be easily verified in almost any district where bees are 

 kept. It appears to me that bees might be of service as an aid in 

 cross-fertilisation in this case ; but it is fair to add that pollen is 

 much needed in early spring when osiers bloom. This shows that 

 the presence of honey in flowers is not the only attraction for the 

 industrious bee. — Yours, &c., Alfred Doxbavaxd. 



Picton, Chester, Dec. 16, 1881. 



PE0FES.S0E XoRDExsKJOLD is going to Russia, where the Govern- 

 ment wishes to consult him on the best method of opening North 

 Siberia to European navigation. 



At the late Archaeological Congress, held at Tiflis, Professor 

 Samokvasoff gave an account of his discoveries in the graves 

 near Pyatigorst. He excavated about 200 places of interment 

 belonging to the stone, bronze, and iron periods. In the larger 

 graves, bronze implements were found with stone ones. As there 

 were in these graves, besides the bones of sheep, several split 

 human bones not belonging to skeletons, he inferred that during 

 the bronze-period the people in that part of the Caucasus were 

 man-eaters. — Frank Leslie's Magazine. 



©ufrirsf. 



[104] — Moo.vs OF Maris and S.itirn. — 1. Can you inform me if 

 Mars has any satellites ? If so, how many ? What is their period of 

 revolution, and at what distance are they from the planet ? — [Mars 

 has two moons, discovered in Angust, 1877; periods of revolution, 

 30h. 14m., and 7h. 38m. ; distances from the planet's centre, abont 

 e,000 and 15,000 miles.— Ec] 2. What are the names of Saturn's 

 two outmost satellites? — [Hyperion and Japetus (the latter the 

 outermost of all). — Ed.] 



[105]. — Ft'XGi axd LiCHEXS. — How are specimens preserved, and 

 which are the best books on the subject Y — J. S. 



[106]— PNErM.VTic Bell.— Will M. Tester (Letter 79, p. 100) 

 kiudly favour me with insti-uctions, " plainly-worded, exactly- 

 described," for making and fixing (down staircases, &c.) a 

 pneumatic bell ; taking for granted — as is really the case — that 

 I have very little native ingenuity? Also stating the price of 

 materials used. If he could possibly supply a simple diagram, 

 where necessary, I should be greatly obliged. — E. R. C. 



[107] — Xame of Star. — How would you pronoimce "Betelgeux," 

 one of the stars (a) in the constellation of Orion. [The question is 

 one for Arabic students. The name Betelgeux is, we believe, a 

 corruption from Ibt al Jauza, the giant's shoulder.— Ed.] 



[108] — After-Images. — These seem to be best obtained, not by 

 closing the eyes and keepiug them closed, but in the act of vigorous 

 winking. When I do this after looking at the sun, I soon obtain an 

 after-image of the following nature : An interior green disc ; round 

 that a narrow circle of red, and beyond, an undefined space of 

 ^'iolet or dark blue. Has this been noted and sufiiciently explained, 

 and, if so, what is the explanation ? Is there any significance in 

 the fact that those three colours arc the fundamental colours ? — 

 MAi. 



[109] — Railway Collisioxs. — From the history of these, are any 

 practical rules deducible for the case of imminent collision (rules as 

 to position and attitude in the carriage, &c.), the observance of 

 which might somewhat limit the power of railway companies to 

 maim and murder us ? — Max'. 



[110] — The Coal Age and the Earth's Ixterxal He.vt. — As 

 an ignoramus, may I ask you whether the earth's own internal 

 heat had anj-thing to do with the gigantic flora of the coal age, on 

 the principle of a hothouse ? Is it supposed that the earth was 

 at one time in a state of intense heat, and will gradually cool like 

 the moon has done ? Does not the temperature increase the deeper 

 you sink into the earth ? What is a good text-book on this snbject ? 

 — Igxobamcs. 



[Ill] — Axes of the Pl.ixets. — WiU you inform me if the axes 

 of the planets are all inclined the same way — that is to say, if the sun 

 and all the planets could be placed in a line at their respective dis- 

 taaces, would all the axes be inclined in the same general direction ? 

 — Oriox. — [The axes of the planets have no community of direction. 

 Our earth's axis points towards Ursa Minor, Jupiter's to a point in 

 the constellation Draco, not far from Omega, Saturn's to a point 

 near the northern extremity of Cephens, and so on. — Ed.] 



[112] — Optical Illusiox. — A remarkable optical illusion is 

 caused by holding the hand, with the fingers close together, near a 

 gas flame. One seems to see through his fingers. What causes the 

 illusion ? Does the light shine through the skin at all ? — G. P. 



[113]^ — Illusory Figures of Traxsparext Solids. — How is it 

 that in looking at the figures of transparent solids that it is possible 

 for you to imagine the figure in two positions ? And what adjust- 

 ment takes place iu the eye whilst so doing ? For instance, in the 

 case of the cube it is possible for you to see it as having a cer- 

 tain face as the front one, and without moving the eyes you can 

 make the opposite face appear as the front one ; or in the prism, the 

 edge xy can be made to appear either at the back or front, just as 

 you please ; but no motion of the eyes need take place. Yet there is 

 a slight effort felt as you change, so to speak, the position of the cube 

 or prism." — P. B. S.— [Mr. Foster will discuss such illusions. — Ed.] 



[114] — M.iRiKE Boiler. — What is the increasing temperattire on 

 the furnace crown of a marine boiler required to keep the steam at 

 a pressure of 1001b. per square inch ; with the scale formed by the 

 deposit of salt within the boiler increasing by sixteenths, from J„ to 

 iin. thick ? How can this be calculated? — Ceaxkshaft. 



[115] — Screw Propeller. — Is there a vacuum on the following 

 side of a screw propeller blade when revoh-ing ? If so, does it 

 materially affect the power of the engine ? .4ny information on 

 either of the above will greatly obUge. — Cranksb.4Ft. 



[116] — John Bull. — Can any reader refer me to the origin and 

 meaning of the term "John Bull." — G. 



[117] ^ Paeallelopipedox or Pakallklepipedon. — Why do 



