38 



HARDWICKE'S SCIENCE-GOSSIP. 



pterostigma reddish ; thorax black spotted with 

 orange, hairy ; abdomen slender, spotted with orange 

 as far as the seventh segment ; front of face white, 

 lower lip black ; upper lip of b white, of 2 black ; 

 anal appendages black. England, rare. Taken 

 near Dorchester. (Hagen.) Length 15 lin. ; exp. 

 26 lin. 



{To he continued.) 



NOTES ON TERMINAL AND SUB- 

 TERMINAL BUDS. 



"W '^HEN a leaf-bud terminates a stem and sur- 

 V V vives the winter, it is that the stem may be 

 continued by it in the following spring. This happens 

 frequently in the horse-chestnut and other trees. But 

 the final termination of a stem is in the flower or a 

 stalk bearing flowers on its sides. Thus, when we 

 speak of terminal buds, we commonly mean flower- 

 buds. The inflorescence of an apple-tree is an umbel 

 with a central flower. This flower, which is truly 

 terminal, is the first to open in a regular way. If, 

 however, the outermost flower of the umbel should 

 dispute with it for precedence, we may be sure that 

 as the lateral flowers open centripetally, that which 

 is next below the centre will not expand so soon as 

 the central flower itself, which does not belong to 

 the lateral series. In the corymb of the pear the 

 same order of expansion is observed, the terminal 

 flower opening first, and that which is next below it 

 last. Botanists who classify the forms of inflorescence 

 under the names of cymose and racemose might 

 dispose of several puzzling cases by calling them 

 ■ corymbose, taking that of the pear-tree as the typical 

 form. More or less resemblance to it is found in 

 most rosaceous plants. When a cluster of bloom is 

 found at the end of a long branch of the apple or 

 pear-tree instead of being on a spur, such a position 

 can hardly be called abnormal, for it may be regarded 

 as the primary condition in which such flowers would 

 appear. No plant can flower at all till its nutritive 

 ■system shall have attained something like maturity. 

 Then its first flower may be expected on the summit 

 of a stem. Lateral branches may bear flowers after- 

 wards, but as the plant grows older, they will tend 

 to be shorter. A short branch is, however, of the 

 same nature as a long one, from which it differs 

 chiefly in its shorter internodes or fewer leaves. 

 The flowers of some plants commonly appear in 

 axillary fascicles, but any plant which is in the habit 

 of producing lateral clusters, each having a central 

 flower, has an inherent right which it will sometimes 

 assert of producing a flower on the summit of a well- 

 developed stem. An annual plant of the labiate 

 order {Galcopsis Ladannnt) sometimes has a central 

 flower on the top of its main stem. Why, then, do 

 some of the best botanists imagine that a central 

 Slower crowning a raceme is formed by the fusion of 



two or more lateral flowers ? It is because of the 

 tendency of such terminal flowers to be synanthic. 

 Such a condition may be regarded as an exaggeration 

 of what commonly takes place in the rue, whose 

 terminal flower commonly has five petals, and each 

 of the lateral flowers only four. 



If I may venture on a hypothetical explanation, 

 I may say that when flowers are collected in a cyme, 

 as of Sambucus or Viburnum, the stem having attained 

 its full length, its vital energy, no longer able to push 

 onwards, tends to lateral expansion, giving origin to 

 a whorl of branches instead of the pair which mii^ht 

 have been in the axils of opposite leaves. In like 

 manner an ordinary flower has its leaves in whorls, 

 not solitary or in pairs like foliage leaves. When, 

 without the intervention of an involucre, or a whorl 

 of branches, a stem which bears a raceme of lateral 

 flowers is abruptly terminated by a central flower, 

 the same tendency to lateral expansion operates more 

 forcibly on all the floral organs, and tends to increase 

 their number. Thus a species of Eranthemum may 

 be found in cultivation with a central flower, some- 

 times having two or three times as many stamens as 

 any of its lateral flowers. 



In the Canterbury bell {Campanula Medhim) such 

 a phenomenon has been observed in connection with 

 what looked like fasciation of the stem. It is perhaps 

 not surprising if such a terminal flower, which is 

 apparently formed of two or more flowers on the 

 same level, and collateral in their relation to each 

 other, should be taken to belong to the series of 

 lateral flowers below them. Such a mistake pro- 

 ceeds from overlooking the facts that a terminal 

 flower, perfectly normal in structure may be fre- 

 quently found in the same species, and that the 

 synanthic flower bears the same relation to the 

 lateral flowers as is observed in the central flower 

 crowning a corymb of the pear, which contains nothing 

 mysterious or abnormal. If we regard the synanthic 

 flowers as terminating a fasciated stem, then if we 

 separate in imagination the fasciated stem into its 

 comjionent parts, each of them would be crowned 

 with a terminal flower which would be the first to 

 open, as the subterminal flower would be the last. 

 The real or apparent fasciation of the stem, and 

 consequent fusion of the several flowers, does not 

 interfere with the order of expansion in which the 

 synanthic flower or head of flowers opens first, and 

 the flower immediately below it last of all the 

 lateral flowers in the same series. 



It is worth knowing that the fusion of several 

 flowers in this manner does not impair their repro- 

 ductive energy. From a capsule proceeding from 

 such a terminal synanthic flower of the Canterbury 

 bell I took a portion of the seeds, and saving them, 

 raised about two hundred plants, which were gene- 

 rally more vigorous than twenty-seven plants raised 

 from seeds of the capsule produced by the sulv 

 terminal flower. The seeds having been ripened in 



