NATURAL HISTORY. 17 



always continues to be of the same kind ; so that it might be supposed 

 that the juices came to the part crude and unchanged in the part, 

 and formed the addition jiist as they were changed. But I am apt 

 to believe that there is a strict analogy between the animal and the 

 vegetable ; for although the vegetable has no stomach to vegetalize the 

 food of the plant, yet I look upon the vegetable to be in every part 

 ' stomach,' and that it vegetalizes all the absorbed juices admitting of 

 such alteration; that the juice goes on to the parts of destination 

 vegetalized, as the blood goes on annualized; and that, there, each 

 juice changes according to the nature of the part to which it is assimi- 

 lated, and according to the action of the parts in which it circulates, and 

 the parts to be formed. In the animal it forms skin, muscle, bones, 

 tendon, ligaments, brain, &c. In the vegetable it forms wood, bark, 

 leaves, flowers, fruits, &c. 



Vegetables which have only water to convert into their own sub- 

 stance are always the best ; therefore it is reasonable to suppose that 

 water 1 is more capable of being perfectly altered into vegetable matter 

 than any other, and a certain quantity is only necessary ; for, when 

 there is too much, it is not so perfectly decomposed as to give all the 

 distinguishing marks of the plant, nor is the plant itself so fine ; its 

 growth becomes luxuriant, but its matter not so good. 



The stem, tendril, and footstalk of the vine have a vast number of 

 spiral threads running through their substance in the direction of these 

 parts. The sensitive plant has the same kind of spiral threads, but not 

 so many. The way to know the above is to break the plant more than 

 half-way through and bend the remainder, and they may be seen passing 

 between the broken parts. 



Animals and vegetables have two different irritations ; one is in- 

 ternal, arising from circumstances within the machine ; the other is the 

 property of being affected by external stimuli. 



Vegetables have a degree of sympathy ; for, if a branch is cut off, 

 the whole plant suffers ; and this much more in some than in others ; 

 therefore gardeners say that such a tree cannot bear the knife 2 . 



1 [Water alone is insufficient ; it must contain atmospheric air in solution, and there 

 must be access of carbon to the plant ; that which the water contains in solution and 

 which is derived from decaying vegetable and animal substances, is peculiarly adapted 

 to nourish the plant, and constitutes fertility of soil. Salts, earths, even silica, are 

 held in solution and thus taken into the system of the plant to be there disposed of. 

 The superfluous water is exhaled from the pores or stomata of the leaves, the oxygen 

 of the carbonic acid is, during daylight, evolved, and the chief materials of the plant 

 are detained, freed from the impurities with which it was blended when absorbed 

 by the roots.] 



2 [The circulation in Chelidonium, observable in the vessels containing the milky 



