BOTANICAL SUBJECTS. 77 



The pitcher of Nepenthes may possibly be explained by a 

 somewhat similar process. We have an ordinary leaf, changing 

 further towards its extremity, into a simple mid-rib, and finally 

 again developing a blade fused by its margin into a tube. 



I know that some have considered the pitcher as a transformed 

 ivater-gland, at the tip of the leaf, but the two toothed margins 

 or wings of the pitcher are to my mind indications of imperfectly 

 fused leaf margins. 



The lid of the pitcher does not appear to be the terminal 

 leaflet. That is represented by a mucro, behind the lid. The lid 

 of Nepenthes Rafflesiana is bilobed, and gives indication of a 

 fusion of tico parts. It may represent \\:iQ fiLsion of two leaflets^ 

 leaving the mucro, or the end of a mid-rib projecting behind 

 them. 



The morphology of the leaves of Sarracenia and Nepenthes 

 are not easy to make out, and any new idea, aided by some 

 teratological specimen, may help on a better conception of the 

 development of these strange leaves. 



It is evident that the lower serial of Cypripeduan and 

 Selenipedium is made up of the fusion of two sepals. In 

 Cypripedkim spectabile I have noticed that some specimens had 

 the lower sepal with two teeth, indicating its origin. It is 

 curious that this fusion, like that of the sexual organs, should be so 

 persistently inherited. 



There are in almost every direction, indications of fusion 

 having been a great factor in modifying plants. 



Up to recently, garden varieties were considered valueless for 

 botanical studies, but whether we call them garden varieties, or 

 field varieties, or prairie and mountain varieties, they come 

 within the scope of Biology, and as such, they are not only 

 interesting and very instructive, but from an evolutionary point of 

 view very important. 



Transposition of Segments. 

 There is another factor which must have been a great modifier 

 of the forms of flowers. I mean transjwsition of floral whorls, 

 in what is called the perianth of Endogens. Botanists often call 

 the outer segments sepals, and the inner ones petals, and Lindley 

 gives them this appellation, in describing orchids. Now, I 

 maintain that these two whorls are sometimes inter-changeable, 



