THK SYCAMORE. 47 



Each of the two or three seed-vessels, which succeed every 

 flower, is furnished with a membranous diverging wing, 

 and it is owing to the presence of this that so many young 

 plants may be discovered in the spring at a considerable 

 distance from the parent tree. When they have acquired 

 their full size, which is early in autumn, they form clusters 

 sufficiently large and conspicuous to alter the pictorial 

 character of the tree. They do not fall off when ripe, like 

 acorns, chestnuts, and other heavy seeds, but remain 

 attached to the branches till the equinoctial gales set in 

 which serve the double purpose of separating them from 

 the stalks and carrying them to some convenient place of 

 growth. If, however, from growing in a sheltered spot, 

 or from any other cause, they still retain their position, an 

 event which frequently occurs, the seed-stalk rots from 

 the effects of the winter's rain ; and the violent winds 

 which accompany the succeeding vernal equinox do not 

 fail to deposit the majority of the seeds in places well 

 adapted for their growth, in full time to receive all the 

 advantages of the genial season which follows. The seed 

 itself is well protected against the severest vicissitudes of 

 weather, first by the horny, or almost woody, case in 

 which it is inclosed ; and secondly, by the copious, soft, 

 and glossy down which lines the seed-vessels, a covering 

 alike impervious to cold and wet. 



It may be that many trees which have been introduced 

 into a strange country fail to propagate themselves exten- 

 sively because the attendant circumstances are not the 

 same in the new country that they were in the old. Were 

 the Sycamore, for instance, to be introduced into a 

 country where no such periodical recurrence of rain and 

 storms took place, and where, also, there was no inter- 

 ference of human agency, it might soon become extinct, 

 inasmuch as its seeds, if kept dry for a year, generally lose 

 their vegetative power. The Oak, if planted in a country 

 uninhabited by man, and where no such friendly depredator 

 as the rook or the squirrel acted the part of a skilful 



