296 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



ful power of nature to make very similar structures for effecting- 

 the same purpose, viz. to catch insects, out of totally different 

 materials ; for while the pitchers of sarracenia and cephalotus 

 were metamorphosed leaves, that of nepenthes was, according to 

 Sir J. D. Hooker, a metamorphosed water gland situated at the 

 apex of the leaf -blade. As a further illustration of the difference 

 in origin of two similar structures, the tendril of the pea con- 

 sisted of metamorphosed leaflets, while those of the vine and 

 the Virginia creeper were made of flower stalks devoid of 

 blossoms. 



A few remarks on the structure of apples, pears, and med- 

 lars showed that these so-called fruits are mainly composed of 

 fleshy stem and bases of the sepals welded on to the carpels ; the 

 outer skin of the latter and the inner one of the former being- 

 undeveloped, the internal tissues of both became confluent and 

 hypertrophied, thus constituting the edible part, the core being 

 only the inner skin of the carpels. 



