362 VEGETABLE METAMOKPHOSES. 



10. — General Observations on the Organs of Plants, and on the 

 Mode in which they are arranged. 



Plants may be said to be composed of numerous individuals, each 

 having a sort of independent existence, and all contributing to the 

 general growth of the compound individual formed by their union. In 

 the case of a tree there are a vast number of buds, each of which is 

 capable of being removed, and of being made to grow on another tree 

 by grafting ; and although each has thus a vitality of its own, it is 

 nevertheless dependent on the general vitality of the tree, so long as 

 , it is attached to it. The same thing is seen in Sertularian Zoophytes. 

 Each of the individuals forming a compound plant is called by Gaudi- 

 chaud a phyton (<pvTov, a plant), and in it he recognises three parts or 

 merithalli {/J-'sgog, a part, and SaXXog, a young shoot), the radicular 

 merithal corresponding to the root, the cauline to the stem, and the 

 foliar to the leaf In Acotyledonous plants the embryo or spore consists 

 of united cells, and it is only after germination that it exhibits these 

 different parts. In Monocotyledons, the embryo consists of a single 

 phyton, with a radicular merithal or radicle, a cauline or tigellus, 

 and a foliar or cotyledon. In Dicotyledons the embryo consists of 

 two or more phytons united, with their foliar merithals (cotyledons) 

 distinct, while their cauline and radicular merithals form each a single 

 organ. 



In tracing the various parts of plants, it has been shown that all 

 may be referred to the leaf as a type. This morphological law was 

 propounded by Linnaeus and Wolff, but it is to Goethe we owe the 

 fuU enunciation of it. Vegetable morphology, the study of forms, or 

 the reference of the forms of the parts of plants to the leaf, is now 

 the basis of organography, and it wUl be observed that in considering 

 the various organs this has been kept constantly in view. The calyx, 

 corolla, stamens, and pistil, are only modifications of the leaf adapted 

 for peculiar functions. It is not meant that they were originally 

 leaves, and were afterwards transformed ; but that they are formed 

 of the same elements, and arranged upon the same plan, and that in 

 the changes which they undergo, and the relation which they bear to 

 each other, they follow the same laws as leaves do. The different 

 parts of the flower may be changed into each other, as into true 

 leaves ; or, in other words, the cellular papiUse from which they are 

 formed are capable of being developed in different ways, according to 

 laws which are still unknown. These changes may take place from 

 without inwards, by an ascending or direct metamorphosis, as in the 

 case of petals becoming stamens ; or from within outwards, by descending 

 or retrograde metamorphosis, as when stamens become petals. 



Bracts are very evidently allied to leaves, both in their colour and 



