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The true signification of the term " recurvus" 

 By Hewett C. Watson, Esq., F.L.S. 



With due deference to the able individuals whose opinions on this 

 word are recorded in the ' Phytologist,' I would suggest that all of 

 them are correct, although too limited in their definitions of the term 

 "recurvus." The value of the prefix "re" may be expressed tolera- 

 bly well by the words " back " and " again," when used in the sense 

 of a change from the actual course of things to one which is contrary 

 thereto. In passive objects (as distinguished from events) a change 

 from the usual state or direction seems to be implied by the use of re. 

 It may thus signify "upwards," "downwards," "outwards," or "back- 

 wards," whichsoever of these is contrary to the usual direction. 



Some examples may make this more clear. A curve in the bill 

 of birds usually brings the tip downwards ; but the upward bend in 

 the bill of the avocet, being in the contrary direction, is expressed by 

 calling it " recurved." The antennae of insects usually extend for- 

 wards from the head ; but if so curved that the direction of the tip is 

 reversed and turned backwards, they are called "recurved." The 

 leaves of plants usually ascend from the bases by which they are at- 

 tached to a stem ; but when this direction is so far reversed that the 

 tips of the leaves point downwards, they are said to be "recurved" or 

 reflexed. In feras, there is usually some convexity of the upper sur- 

 face, the edges of the frond bending downwards ; but if the direction 

 of the edges becomes reversed and turned upwards, which is contrary 

 to the usual direction, the term "recurved" will here correctly express 

 the change. 



By a larger definition of the term " recurvus," so as to include any 

 direction contrary to the usual or principal direction, it will take in 

 all the special examples, whether their curves are upwards, down- 

 wards, outwards or backwards. 



The name "concava" really appears less aptly given to Mr. Bree's 

 fern ; since it does not necessarily imply a concavity of the upper 

 surface. A hat and a wine-glass are each concave, though the con- 

 cavity is upwards in one, downwards in the other ; but the brim of an 

 English hat, as well as that of a champagne-glass, is recurved, because 

 it is bent in a direction contrary to the principal and usual concavity 

 of hats and wine-glasses. 



Hewett C. Watson. 



Thames Ditton, April, 1845. 



