Botanical Society of London, 209 



the various changes which occur in the condition of the vegetable 

 organs ; both such as are normal, as the transmutation of leaves into 

 the several floral organs, as well as such as are abnormal, and occur 

 only accidentally. 



Taking the above as the definition of the subject, we immediately 

 see its divisibility into two heads ; the first of which treats of regu- 

 lar metamorphoses which are connected with the natural structure 

 of all vegetables ; while the second includes those irregular or acci- 

 dental metamorphoses which result from an imperfect or redundant 

 performance of the several changes noticed under the first head. 



These last influence particular plants or parts of plants, and occur 

 only in occasional instances. To this division belongs the considera- 

 tion of double and other monstrous flowers. 



Of regular metamorphoses. — The great principle of regular mor- 

 phology is, that the various floral organs are but modifications of 

 one common type, which is the leaf. 



Lindley endeavours to give Linnaeus the credit of having been 

 the author, or at least of having suggested the idea of this great fun- 

 damental principle, and in proof of this opinion quotes passages from 

 his ' Systema Naturae ' and ' Prolepsis Plantarum,' in which the 

 theory is imperfectly hinted at. At his suggestion the subject does 

 not appear to have been taken up ; nor was it at all until Goethe 

 published in 1770 his work ' On Vegetable Metamorphosis.' With 

 a knowledge of the character of his poetical writings, it hardly need 

 excite surprise, that botanists of the day should have been sceptical 

 on a subject so new, and at first sight so opposed to the dictates of 

 common sense. By the appearance of this work however the atten- 

 tion of botanists appears to have been roused to the subject, and the 

 result of their investigations tended to confirm the correctness of his 

 views. 



Leaves are in many instances entirely wanting, or exist only in 

 the degenerated forms of scales and spines. In these cases there is 

 hardly any part of a plant which is not susceptible of being modified 

 and rendered capable of performing the functions of leaves. For 

 this purpose we find the excessive development of the stem which 

 obtains throughout lactaceous plants ; also the stem is furnished 

 with leafy wings or expansions which run down its sides, as is seen 

 in Acacia ciliata, &c. The petiole, in the form of the Phyllodium, 

 frequently takes upon itself the office of the leaf, as in most of the 

 Acacias from New Holland. The same functions are frequently 

 discharged by the peduncle, as in Ruscus, Asparagus, &c. ; and this 

 appears to be the true character of the leafy organs of ferns, the true 

 leaves of which exist in the degenerated form of scales, known by 

 the name of ramenta. 



The calyx consists of a series of leaves arranged in a whorled 

 manner round the axis, either distinct, or more or less combined, 

 according to the character of the plant under consideration. 



To prove our position with this series of a genus, we must refer 

 to the condition of parts in Cactacece, where we have a gradual trans- 

 ition from bracteae to sepals, so that it is impossible to say where 



Ann. $ Mag. N. Hist. Vol, x. P 



