June 12, 1890] 



NATURE 



1^5' 



to get ten more or less distinct varieties, besides others 



(which are more or less indistinct. The great variability 

 of this species is now well known, and the seedlings of 

 Abies subaipina, Engelmann {A. lasiocarpci of Hooker), 

 famish another illustration of the same tendency. These 

 seedlings may be the result of cross-fertilization between 

 varieties, or they may be reversions to an earlier con- 

 ilition ; at any rate, of whatever nature they are, they are 

 not " sports" in the sense here intended. 



Next, sports are not mere stages of growth. Most 

 plants put on a different appearance at various periods or 

 stages of their growth, and sometimes these changes 

 are very remarkable. The Retinosporas of our gardens 

 furnish us with excellent illustrations. Retinospora (or 

 more strictly Thuya) pisifera exhibits during its growth 

 very different appearances in its foliage. There is the 

 squarrose form and the plumose form, the golden form, 

 the silver form, the pendulous form, the thread-like form, 

 the upright form, and perhaps others. All these, how- 

 ever, are not separate entities ; they may all occur on the 

 same bush. If cuttings or if grafts be taken from the 

 sporting branches they may be reproduced almost in- 

 definitely. 



Barring the mere colour variation, these forms are but 

 stages in the growth of the plant, occurring with more or 

 less regularity and in greater or less degree of prominence 

 in all the individuals of the species, as may be inferred 

 from watching the growth of seedlings in a seed-bed. 



Other illustrations of variations arising during growth 

 are afforded by the differences often observable in the 

 foliage on the flowering branches as contrasted with that 

 on those branches which bear no flowers. The common 

 Ivy furnishes an illustration. The short contracted shoots 

 of the Laburnum, or the Apple, known as " fruit spurs," 

 constitute other examples. 



Another form of variation in flowers is that connected 

 with difference of sex. A " pin-eyed " Primrose does not 

 greatly differ in appearance from a " thrum-eyed " one, 

 yet the difference between them is precisely of the same 

 character as that between the variously formed flowers 

 of some species of Catasetum and Mormodes. So utterly 

 different are the male and female flowers of some of these 

 species that they were at first placed by very competent 

 botanists in different genera. It was only when the 

 Protean plants produced all the forms of flowers on 

 one and the same spike, that it was seen that, so far 

 from belonging to different genera, they did not even 

 belong to different species. It was left to Darwin to 

 show what this paradoxical variation really means ; and 

 now, when we meet with a case of the kind, we say, 

 "Ah ! yes ; only a sexual form," just as if we had known 

 all about it from our earliest years, and very possibly, in 

 our haste, mixing up, or, at least, not discriminating 

 cases of a different nature. But this is not what we 

 propose to discuss just now ; we simply say that these 

 cases, though often so designated, are not sports, at least 

 in our acceptation of the term. 



What, then, are sports ? We have already character- 

 ized them as " bud-variations," but we must give some 

 further indication of their peculiarities : First, as to the 

 suddenness of their production. A tree or a shrub, all on 

 a sudden and without any cause that is apparent to the 

 eye, will put forth a bud, which, as it lengthens into a 

 shoot, displays leaves of a different character from any that 

 the plant has hitherto produced, which have no definite 

 relation to any particular stage of growth ; and which are 

 quite different from any that under ordinary circumstances 

 the plant in question has produced or is likely to produce 

 in future. In short, the occurrence is sudden and un- 

 foreseen. Gardeners, of course, avail themselves of these 

 variations. They remove them, bud them, graft them, 

 strike them from cuttings, or, in some way or another, 

 endeavour to perpetuate the variety, and thus have 

 originated many of our cut-leaved Beeches, Maples, and 



NO. 1076, VOL. 42] 



Limes. Thus, too, may have originated some of our 

 weeping trees and some of our pyramidal shrubs, though, 

 for the most part, these have, as I believe, originated as 

 seedling variations. 



Not only do these variations occur suddenly, but they 

 are very local in their manifestation. One particular 

 shoot " sports," while all the rest remain in their normal 

 condition. It is very different in the case of seedling 

 varieties, where the whole system of branches and leaves 

 is more or less affected. 



Another and a most remarkable feature about these 

 sports is, that they sometimes occur simultaneously in 

 widely different localities ; thus the same sport of a 

 Chrysanthemum " turns up " about the same time, not 

 only in different nurseries in this country, but also on 

 the Continent. This may be because all the plants in 

 question have originated from one and the same stock. 



These, then, are the special characteristics of a true 

 sport. Illustrations could be given by the hundred ; but 

 neither time nor space permit, nor, indeed, for our present 

 purpose, is it requisite to do so. Whoever will investi- 

 gate the cause of these sudden outbursts of local varia- 

 tion must, of course, sedulously examine each case for 

 himself according to the measure of his ability and of his 

 opportunity. The circumstances, the history, the progress, 

 the anatomy of each particular sport must be investigated, 

 both absolutely and in relation to similar outgrowths in 

 other plants. Until this is done— and it has not been 

 done yet — any explanation as to the cause of the pheno- 

 menon iTiust be a matter of speculation. Still, we cannot 

 help guessing, and though we may be wrong in our sur- 

 mises, at least the process does good by setting us ob- 

 serving and thinking. Observing and thinking are pro- 

 cesses valuable to all of us, but in a particular degree to 

 those who practice the cultural arts. And so it happens 

 — or, at least, we will hope so — that although the causes 

 which have been assigned for these changes are various, 

 some, perhaps, utterly wrong, others partially so, and all 

 more or less inadequate to explain the whole of the phe- 

 nomena, yet some advantage may accrue from the dis- 

 cussion. An indirect benefit is better than none at all, 

 and anything which enforces us to take some measure of 

 the extent of our own ignorance is likely to be beneficial. 

 We should never be a bit the better if we simply acknow- 

 ledged our ignorance, as, indeed, we needs must do in any 

 case, but directly we attempt to find out in what par- 

 ticulars and in what degree we are ignorant, then there is 

 some hope that some portion of our " nescience " may be 

 dispelled. Under this impression we may allude to one 

 or two of the assigned causes of sporting. External 

 causes are those which the gardener most generally in- 

 vokes. For him a sport is usually the consequence of 

 some alteration in the nutrition of the plant. It gets too 

 much or too little food, or the food is not of a suitable 

 character — containing too much of one thing, too little of 

 another, or the climate is charged with the results ob- 

 served. It is very convenient to have the weather to 

 blame ; it may be too hot or too cold, too moist or too 

 dry, too brilliant or too obscure ; or the soil may be at 

 fault, the drainage may be defective, the earth not suffi- 

 ciently aerated, its temperature too high or too low. Com- 

 bined action of some of these conditions is, of course, 

 possible, intermittent action equally so, whilst we, in this 

 country, are abundantly familiar, first with one thing in 

 the way of the weather, and immediately afterward with 

 another. It is, therefore, not surprising if some gardeners, 

 without troubling themselves much to see how the ex- 

 planation fits the facts, do attribute "sports" to such 

 causes as we have mentioned. To our thinking, the ob- 

 jections to this kind of explanation are fatal. External 

 circumstances are, no doubt, potent enough to effect very 

 great changes indeed. We are daily witnesses of them ; 

 but they do not produce the kind of change which we 

 know as " sports." On the contrary, sports occur some- 



