SCIENCE-GOSSIP. 



237 



giving an even well-defined outline as seen 

 against the sky, and contrasting strongly with 

 the loose, irregular and parallel branchlets of 

 the ash. 



The Maple. 



The maple (Acer campestre, Linn.) is rather a 

 small tree, and from its partiality for hedge-rows 

 is often subjected to periodical cropping, and 

 is thus prevented from exhibiting its full-grown and 

 characteristic features, 

 which, as will be seen, 

 somewhat resemble 

 those of its relative, the 

 sycamore. The general 

 arrangement of leaves 

 and flowers, and con- 

 sequently of branches 

 also, is much as in the 

 sycamore, the leaves 

 being opposite in cross- 

 ing pairs, and the in- 

 florescence terminal on 

 short leafy shoots of 

 the current year. In- 

 stead, however, of being 

 arranged in pendulous 

 racemes, as in the syca- 

 more, the flowers of the 

 maple are borne in. 

 erect corymbs at the 

 extremity of the small 

 leafy shoots ; and these 

 shoots are longer in 

 proportion, having often 

 three (or perhaps more) 

 joints or internodes 

 with pairs of leaves, 

 whilst in the sycamore 

 there are rarely, if ever, 

 more than two such 

 joints. 



The young branches 

 of the maple are also 

 more slender than in 

 the sycamore, and the 

 internodes shorter, thus 

 the leaves, although 

 smaller, are more 



crowded. There is a 



further peculiarity also in the tendency shown 

 by the maple to form accessor}- buds about 

 the base of the previous year's branchlets. A pair 

 of such buds is often found just below the origin 

 of the last year's branchlet, and again another pair 

 or pairs above it. These buds eventually develop 

 into small shoots, and thus cause the spray wood of 

 the maple to be more crowded than in the sycamore. 

 In its early growth the maple produces straight 

 branches with internodes of about one and 



three quarters to two and a half inches in 

 length where vigorous, whilst on the side shoots 

 and weaker growths the internodes are only 

 from a quarter to three-quarters of an inch in 

 length. The branches give rise to secondary 

 branches at the nodes or joinings, these se- 

 condary branches or branchlets being afterwards 

 supplemented by the accessory shoots which have 

 been mentioned. 



The flowering ten- 

 dency is first manifested, 

 as in the sycamore, by 

 the small lateral branch- 

 lets, their parent branch 

 continuing meanwhile 

 to lengthen, season 

 after season, in its 

 original direction. 

 When, however, the 

 terminal bud gives rise 

 to a flowering shoot 

 instead of a leafy one, 

 there is no further 

 lengthening of that 

 branch ; all further 

 growth consists in the 

 repeated forking of the 

 small flowering branch- 

 lets which arise from 

 the buds formed at the 

 close of each season 

 in the axils of the last 

 pair of leaves, i.e. that 

 pair which is imme- 

 diately at the base of 

 the inflorescence. The 

 flowering shoots in the 

 earlier life of the tree 

 and branches are gene- 

 rally longer in pro- 

 portion than in the 

 sycamore ; but as the 

 maple advances in age, 

 and the flowering 

 sprays become more 

 numerous, they become 

 shorter and shorter, 

 assuming more the 

 character of spurs. I 

 find also that, in age, the pairs of buds which are 

 formed at the ends of the flowering shoots do 

 not develop so uniformly as in the earlier life of 

 the tree, one or other of these buds often remaining 

 dormant, or at best giving rise to a much smaller 

 shoot than its fellow ; thus the opposite decussating 

 (crossing) growth is somewhat departed from. 

 The same tendency on the part of one of the pair 

 of buds to remain dormant may also be noticed 

 in the sycamore. 



Sycamore, bei-ore reaching Flowering State 



