0;^2 



knowledge: 



[Apbil 20, 1883. 



for oxi.stencp. It is easier to fertilise five or ten carpc-ls, 

 with six or a dozen seeds apiece, than to fertilise 

 fifty with one in each. A glance at a bunch of marsh- 

 mari-'olds in various stages of maturity ^vill show at once 

 the mllonnl.-^ of this principle. In the youngest flowers, 

 the outermost stamens only are mature; as they grow 

 older, the inner rows of stamens ripen one after another ; 

 and at last the carpels themselves become fit to be impreg- 

 nated with pollen from a neighbouring blossom As the 

 bee (or other visitor) bends over the different flowers, he 

 collects pollen from the younger ones, and conveys it imme- 

 diately to the sensitive surfaces of their elder sisters, ihus 

 a sinMe act suflices to fertilise the whole set of carpels, 

 which have accordingly been reduced from the irregular 

 mob of the buttercup to a single row of five, or soinetiines 



remains at bottom identical throughout, but it fills itself 

 out more or less, according to the supply it obtains 

 of food and sunshine. Hence the marsh-marigold, growing 

 as a rank perennial with a rich and almost bulbous root- 

 stock in fertile marshy places, can aflbrd to produce very 

 large and well-filled leaves ; while the lesser celandme, a 

 smaller plant of somewhat similar habits, but possessing 

 only little sausage-shaped tubers, and growing in less 

 favourable situations, can not attain the same breadth of 

 leaf, though it rounds each leaf to an equal degree ; and 

 the meadow buttercups, subjected to the fiercer competi- 

 tion of the summer grasses and clovers, have to divide up 

 their foliage into numerous much-cut segments, in order ta 

 intercept whatever little light and air is permitted to reach 

 them by their greedy neighbours. 



a double one of ten, for the numbers fluctuate considerably 

 between these two extremes. Each carpel contains several 

 seeds, and grows out at last into a little dry brown follicle. 

 Such economy of parts is one of the best tests of relative 

 evolution in the vegetable hierarchy. 



It is curious to note, however, that while all this deve- 

 lopment has taken place in the flowers, the foliage still 

 remains essentially true to a very primitive buttercup type. 

 The beautiful, big, glossy leaves of the marsh-marigold are 

 almost identical in shape, texture, and, in fact, everything 

 but size with the much smaller leaves of a true buttercup, 

 the lesser celandine, now flowering abundantly in all the 

 meadows and hedgerows around us. Such constancy is 

 interesting, but by no means unusual : for in like manner 

 the globe-flower almost exactly reproduces the other type 

 of Imttercup foliage so familiar to us all in the common 

 English meadow species. The reason is that the cir- 

 cumstances of the two similar plants are in both 

 cases all but precisely the same. The family leaf 



THE WARNER OBSERVATORY. 



(EOCHESTER, X.Y.) 



By G. W. Elliott, M.A. 



To the Edit(yr of Knowledge. 



SIR, During my recent residence in London I read 

 Knowledge with interest every week, and this will 

 perhaps explain, and in a measure atone for, my freedom 

 in addressing vou. Constant perusal of a paper so tho- 

 roughly and refreshingly infused with an active personality 

 as is Knowledge makes tlie reader feel as if he were weU 

 acquainted with the Editor, even though he has never seen 

 him. .^ 



On my return to the States I find that the V j™^*" 

 Observatorv has been completed, and is now occupied by 

 Mr. Lewis" Swift, Ph.D., R.A.S., the well-known comet- 

 finder. Presuming that vou would be interested in learning 

 all about the latest addition to astronomical facilities m the 



