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HA RD WICKE ' S SCIENCE- G OSS I P. 



SYCAMORE SAMARAS. 

 By Edward Malan, F.L.S. 



SOME time ago* a charming paper appeared in 

 these pages on " Frog- Spawn,'' which led me 

 last year to make similar observations en the seeds of 

 the common sycamore {Acer pseudo-plataniis). 



Every one is more or less familiar with these brown 

 winged seeds, which strewed the March meadows. 

 They are one of the surest signs of spring, and a 

 basket may be filled with them in ten minutes. 

 Wherever the storms of winter have blown them, 

 wherever there is a pennyworth of soil to be found, 

 by windy copse, by silent stream, by dusty roadside — 

 there, in countless numbers and all unnoticed, their 

 struggle for life begins. And it often is a hard 

 struggle. For one seed that survives, how many 

 millions must perish ? Browsing animals, hob-nail 

 boots, unkind fate, and death in a thousand shapes, 

 meet them at every turn. Therefore what can I do 

 better, a bachelor, in the kalends of March, than 

 rescue one of these seeds from oblivion ? 



Throughout February, unless the weather is very 

 mild, the seeds remain, as they have remained since 



Fig. 113. — Flowers of Sycamore. 



November, in situ. There is no life visible — no 

 promise, but only the uncompromising dry husk of 

 things. About February 25, however, Nature, re- 

 orient out of dust, turns in her sleep, and a tiny root, 

 yellow and yellower at the tip, emerges, feeling faintly 

 after the sunny earth. 



Now just please go out, and select some of these 

 seeds, and watch their growth. You will find them 

 singly or in paiis. Every individual seed, with its 

 wing extended like the wing of a moth, is called 

 a samara. If the seeds are joined in pairs, the 

 first thing to notice is that they are attached nose 

 to nose in an affronted position. Place a pair of 

 these seeds in the sun on damp earth under a bell- 

 glass. In a few days they will begin to separate 

 (Fig. 115), and it will then be plain that the nose 

 of each seed is seamed with a longitudinal slit or 

 suture, like the hilum in the common bean. Each 

 eed is attached to the peduncle or flower-stalk by a 

 slender thread, and the remains of the pistil appear 

 between. Even in so simple a thing as this attach- 

 ment of the seeds to the stalk, great Nature has 

 displayed a wonderful deal of skill and forethought. 



* March 1S82. 



The threads start from the stalk, and extend to the 

 point of the suture farthest from the stalk, forming an 

 outline like the letter M. By this means the sap 

 flows into the wings up the length of the suture, and 

 the root is able to emerge at the point nearest the 

 peduncle. If the threads were attached elsewhere 

 they would interfere with the escape of the root, less 

 sap would be supplied, and the means of attachment 

 would not be so secure. 



In three or four days (Feb. 2S), the root becomes 



Fig. 114. — Wings of Samara, brown on Sept. 4, iS 



Fig. 115. — Samara of Sycamore (in situ Feb. 19, 1885J : 

 n, samara; />, pistil, c, peduncle ; d, capsule; e, pteridion- 



pink near the hilum, and a furry haze of microscopic 

 rootlets appears. Growth then proceeds rapidly. 

 By March 7 the seed-leaves or cotyledons are visible, 

 and the head of the capsule, lined with fine hair 

 {simarre), ruptures along its proper lines. In a few 

 more days (March 11), the cotyledons, which are 

 carefully wrapped up in a tunic, are free and creased, 

 and the capsule and tunic are no longer needed. 

 The method of folding the cotyledons is very clear. 

 They are folded up so as to occupy least space, i.e_ 



