Nov. 6, 1884] 



NATURE 



15 



time, and independently one of the other, by Wolf and 

 by Linnaeus, and thirty years before Goethe propounded 

 a similar notion. Moreover, it brings into prominence 

 not only the morphological relation of shoot and flower, 

 but one manner in which the time of production of the 

 shoot and of the flower respectively may be varied, a 

 subject having an immediate bearing on the question of 

 unseasonable flowering. If, says Linnaeus {Prolepsis, ^ ni. >, 

 " a shrub which has been grown in a pot, and has borne 

 flower and fruit every year, be transferred to richer soil 

 in a hot-house, it will produce for many years numerous 

 leafy shoots, but no fruit. From which it may be inferred 

 that the leaves are produced from the same source whence 

 the flowers previously sprang, and so in turn what now 

 tends to form leaves would, by this agency of Nature, be 

 converted into flower if the same tree were again placed in 

 a pot so as to confine the roots ; hence gardeners desirous 

 of obtaining a more plentiful crop of strawberries, cut the 

 fine roots of the plants in spring before they transplant 

 them, in the hope that they will produce more abundant 

 flowers and fruit." Here we see the same principle laid 

 down as that upon which gardeners act when they wish 

 to secure flower and fruit by cutting off the supplies, 

 and thus making the plant, to a greater degree, de- 

 pendent on the elaborated reserve stored up in their 

 tissues. This is effected by growing plants in small pots, 

 root-pruning, transplanting, ringing, and other processes, 

 all of which tend to diminish root-absorption, and by dis- 

 turbing the balance between it and other processes, to 

 check vegetation, and in so far to promote the formation 

 of flower. Charles Martins relates the production on a 

 very large scale of inflorescence on the Agave, in 

 Algeria, as the direct consequence of the excision 

 of the leaf-buds by a troop |of French cavalry, who 

 hacked the plants with their SLibres as they passed, 

 and thus, by preventing or checking growth in one 

 direction, stimulated it in another. In like manner I 

 have seen flowers produced on the " suckers " of Ailanthus 

 glandulosa when the plant was quite young, on the roots 

 of Pyrits japonica, and on a sucker of Agave, as the result 

 of injury, probably in all, certainly in some, of the instances. 



The frequent production of flowers out of season on 

 newly transplanted trees is accounted for in like manner. 

 But many trees are flowering this autumn which have 

 not been slashed with sabres nor moved by more peaceful 

 weapons, e ne such tree, a horse-chestnut, I lately 

 (September) saw, in which one limb, and one only, was 

 full of young leaves and flowers, while the remaining 

 limbs were fast losing their foliage. The reason for this 

 partial production of bloom I was not able to divine ; 

 possibly it may have had some relation to injury to a 

 certain portion of the root-system in more or less direct 

 connection with the particular branch, but I have no 

 evidence to offer in support of such a guess. 



In speaking previously of one modification of unsea- 

 sonable flowering dependent on activity protracted beyond 

 the customary period, it was mentioned that the flower 

 was in such instances developed at the ends of long 

 slender shoots formed during the course of the sunnier. 

 In such cases the shoot ends in a flower-bud instead of 

 a leaf-bud as is usually the case. The conditions are no 

 longer favourable for the extension of the shoot, and the 

 energy of growth is diverted to the production of flower. 

 But in the laburnum, in many fruit-trees, such as the 

 apple and pear, the fruits are normally borne on short 

 thick branches called by the gardeners " spurs." These 

 are very interesting physiologically, as possessing inter- 

 mediate transitional characteristics, such as those before 

 alluded to, between vegetation and seed-production. 

 In form, these spurs are short and thick, with very narrow 

 interspaces between the leaves, and they bear a cluster of 

 buds which ultimately all develop into flowers, or in 

 which the central and terminal one is a leaf-bud. Inter- 

 nally these spurs are soft and spongy, with a great prepon- 



derance of cellular over fibro-vascular or woody tissue. The 

 cells are moreover filled with starch. We have evidently 

 here got to do with store-places, analogous to that fur- 

 nished by the tuber of the potato and other formations, in 

 which food, or matter capable of conversion into food, is 

 stored up for future use at the growing points ; in this 

 case for the formation of fruit. Flowers are occasionally 

 produced on these spurs out of due season : the flower- 

 bud destined for a following season bursts into activity this 

 year, affording an instance of a Xxv&flenraison anticipee ; 

 but more often, according to my observations, when an 

 untimely flower is produced (especially in the apple), it is 

 from the development of a flower in the central bud of the 

 spur, which is usually a leaf-bud as above stated. In such 

 a case, then, we have not only an alteration in the character 

 of the bud, but a change in the period of its expansion. A 

 converse illustration to that just given is afforded by a 

 case recorded by Mr. Berkeley, in which a bud of a 

 walnut, which in the ordinary course of things should have 

 produced a female inflorescence in the following spring, 

 was developed in the autumn as a leafy 



Renewal of growth after temporary arrest, " recru- 

 descence" as it is sometimes called, occurs normally in the 

 pine-apple, Eucomis, Metrosideros, and other plants. 

 Abnormally, I have met with it in Cytisus nigricans, the 

 common wallflower, CEnothera, and many others. It 

 hardly differs from the first category mentioned in this 

 note except in the fact that the new growth is the direct 

 continuation of the old and not an entirely new lateral 

 formation. It differs from the terminal bud of a " spur.' 

 in that the latter is normal as to position even if 

 developed out of season, whereas in the class of cases 

 now under consideration the activity of the growing point, 

 which usually ceases with the development of the last 

 flower, is exceptionally continued. 



One other circumstance deserves mention, and that is 

 the rarity with which true fruit, or at least ripe seed, is 

 produced as a result of these untimely flowers. Some- 

 times, of course, ripe seed is produced ; a plum is before 

 me as I write the seed of which is as perfect, to all 

 appearance, as that of the first crop could have been. 

 But in the majority of the pears and apples which come 

 under one's notice'at this unseasonable period, the fruit is 

 there (in the popular sense), but the core, which is in a 

 botanical sense the true fruit, is absent, or, if present, the 

 seeds it contains are usually abortive. Botanical readers 

 will readily see the morphological reason why, and phy- 

 siologists will recognise that in such cases the deviation 

 from the ordinary course is not so great as it appears 

 upon the surface, and the action of the " environment " 

 is not so potent as it appears to be at first sight. 



To sum up : these cases of unseasonable flowering 

 appear to be due either to continuous growth and 

 development, to renewal of growth after a longer 

 or shorter period of arrest, or to the development 

 of a flower-bud in the place of a leaf-bud. What pro- 

 duces these changes ? To this no more precise answer 

 can be given than has already been afforded. The 

 absolute nature of the change, structurally and morpho- 

 logically, depends upon the nature of the inducing causes, 

 and va'ries accordingly ; the degree of change may 

 depend simply on the increased or prolonged intensity of 

 action of the same causes which promote natural growth. 

 Maxwell T. .Masters 



NOTES 



The Washington Prime Meridian Conference closed on 

 November 1. Protocols were approved, which will be made 

 the basis of an international convention, fixing Greenwich as the 

 prime meridian. 



Manchester is determined to have the British Association 

 in 18S6, and its invitation will almost certainly be accepted. 



