GALLEBIO'S TREATISE ON THE CITRUS FAMILY 



l he vegetable kingdom details escape the obser- 

 vation of the physiologist, and it is extremely 

 difficult to give some of the comparative anato- 

 mical appearances of vegetables, but it is for 

 this reason no less true that differences may ex- 

 ist and be as unchangeable as In the animal king- 

 dom. Every species has its determined forms, 

 which may be destroyed but not modified, and 

 whatever the nature of the stock which nourishes 

 the plant, it will always give the product proper 

 to its species. 



ART. IV. Influence of culture and soil on plants. 



Culture and climate have appeared to many 

 writers more powerful than the graft, and they 

 have attributed to them the very decided changes 

 in the secondary characteristics of trees. It 

 is principally to the force of culture that they at- 

 tribute the sensible difference existing between 

 the wild and cultivated trees. But it is easy to 

 see that this is a mistake in their judgment, and 

 that they attribute these differences to culture or 

 the graft, merely because these are the processes 

 which always accompany the individuals which 

 undergo a change and become improved fruit, 

 and because these are the means of multiplying 

 the number of the improved individuals. Where- 

 as these are mere accidents ; they have, because 

 constantly used, been considered the causes of 

 the changes in the fruit. 



Nature gives some trees which bear ordinary 

 fruit and others which bear fine fruit. The first, 

 always being grafted when in our gardens, bears 

 its own peculiar wild fruit only when found in 

 the woods; and the cultivator who sees them 

 there in a degraded condition concludes that 

 this degeneration is due to the want of cultiva- 

 tion. The trees bearing fine fruit, being seen 

 only in a state of cultivation, and multiplied by 

 the graft only, the cultivator, ignorant of the 

 origin of their ancestors, judges that they owe 

 their improvement to the graft and the culture 

 which they have undergone. I say the cultiva- 

 tor judges in this manner on account of this ig- 

 norance of the first original tree which gave these 

 different results which he observes; because 

 there has never existed a writer, to my knowl- 

 edge, who has carefully noted how one of these 

 changes has occurred. They all speak of the 

 changes and note the difference which exists be- 

 tween those individuals found in the woods and 

 those found in the gardens, but no one has seen 

 this change take place on one and the same in- 

 dividual. I say all see it through the dimness of 

 ages, and their conclusion is the result of con- 

 jecture rather than of observation. 



But a close and continuous attention to nature 

 will show that these differences, which exist in 

 two distinct individuals, as, for instance, the pear 

 of the forest and the pear of cultivation, never 

 appear successively on the same individual. I 

 call an individual the plant which exists on its 

 own stock, and which enjoys the life given it by 

 Nature, and I also term an individual the collec- 

 tion of all the plants which proceed from a single 

 germ, and consequently form only one single 

 plant, which may be multiplied without changing 

 its character, either by passing successively on to 

 an infinite number of stocks as a graft, or by form- 

 ing by means of slips an infinite number of stocks 



of its own, having a root in the earth, and pro- 

 longing in this manner its own life, as well as 

 that of the species, and thus varying infinitely 

 (he places and modes-of its existence, but always 

 bearing in itself the principles of organization 

 received in its conception. 



The individual which perished on the root 

 where it germinated, and that which renews for 

 the millionth time, it may be, its life, in a graft or 

 a slip, have a single and common origin, and 

 hence are one and the same individual. ^This in- 

 dividual, though infinitely multiplied, will always 

 bear in the numberless subdivisions of its being 

 the same characteristics and the same aspect 

 which it had in the beginning. To illustrate, 

 take the sugar-cane. In India, beyond the Ganges, 

 there are several varieties of this plant which are 

 propagated by seeds, but in -San Domingo, where 

 it is reproduced by slips, only one variety is 

 known. It has been cultivated there since 1606, 

 with different methods and a variety of soils, and 

 still remains unchanged. Neither the processes 

 of cultivation nor the difference in soils have im- 

 proved it in the course of two centuries, and the 

 only reason why it has not degenerated is be- 

 cause it has always been multiplied by cuttings. 



This fact is perfectly in harmony with the 

 theory of the manner 'in which culture affects- 

 vegetables. Nutrition is the most powerful mean? 

 by which they can be influenced in cultivation. 

 The nourishing juices, of which the earth is the 

 principal vehicle^ are everywhere of the same na- 

 ture; chemistry has proved that the same ele- 

 ments unite to form, the acorn in the oak tree^ 

 and the orange in the orange tree. It is in the" 

 different organs of the diverse genera of vege- 

 tables that these same principles are decomposed, 

 elaborated, and finally acquire forms and prop- 

 erties widely different from each other. 



Now, can we suppose, without wounding the 

 principles of sound philosophy, that this passive 

 material, which is designed only to receive modi- 

 fications from the different agents by which it ia 

 elaborated and used that this can react upon 

 those organs or agents and change their exist- 

 ence, a work so marvellous that Nature only can 

 perform it ? 



It has been held that th'e multiplicity of petals, 

 which form double flowers, and the certain lusti- 

 ness of some varieties arc due to a superabundance 

 of nutrition. But this formation of petals is not 

 the simple development of a principle pre-exist- 

 ing in the flower. It is a real change of the 

 male and female parts into corollas ; andihe lux- 

 uriance of these beautiful varieties bears in the 

 leaf and in the fruits new forms, which distin- 

 guish them from others and constitute them dis- 

 tinct races. 



Nature has fixed for all races a maximum and 

 a minimum of development which no cause can 

 surpass. When a plant has little nutriment it 

 becomes feeble and languishes, but it will die 

 before departing from the characteristics of its 

 species. If well nourished it attains the max- 

 imum of its growth, but if engorged it refuses 

 the superabundance, or, if forced to absorb, it is 

 injured; its canals are blocked up, its organs 

 affectecl, its vital functions changed, and it per- 

 ishes. The facts wo possess are in harmony with 

 these principles. We find double flowers only in 

 species which are multiplied by seed. Thosf 



