THE ANNALS 



AND 



MAGAZINE OF NATURAL HISTORY. 



[SECOND SERIES.] 

 No. 62. FEBRUARY 1853. 



VII. — On Relative Position; including a neiv Arrangement of 

 Phanerogamuus Plants. By B. Clarke, F.L.S. &c. 



[With a Plate.] 



Pakt I. 



On the Position of the Rajjhe. 



The position of the raphe in anatropal ovules is a chai'acter 

 which has hitherto attracted but partial attention, yet is, as will 

 be seen, one of much constancy, being rarely vai'iable in the 

 same natural order, and the exceptions also, in most if not in all 

 instances, being readily explained. 



For the purpose of giving to this physiological character a 

 more definite form, I will endeavour in the first place to show 

 what is the most usual position of the raphe, where each margin 

 of the carpel bears a single row of ovules, as in Paonia, and 

 afterwards notice the variations of its position, more especially 

 where the ovule is single. 



The most usual position of the raphe where the ovules form 

 two rows — one row to each margin of the carpel — is the same 

 throughout the families of phanerogamous plants, viz. the raphes 

 of the two opposite rows lie in apposition with each other in the 

 mesial line of the carpel, or, in other words, are turned towards 

 each other, and the. ovule bends downwards so as to be in con- 

 tact with the parietes. And hence it may be a question whether 

 this is not the normal position, as it is common to Endogens and 

 Exogens, of which Amaryllidese, Liliacese, Ranunculacege, and 

 Passifloraceffi contain well-marked examples. 



But when anatropal ovules are very numerous in consequence 

 of each placenta bearing more than a single row, this regularity 



Ann. l^ Mag. N. Hist. Ser. 2. VoL-ai. 6 



