82 Mr. B. Clarke on Relative Position ; 



of position is not always observable, further than that the raphe 

 usually retains its lateral position as in Cucurbitacese ; and cam- 

 pylotropal ovules also not unfrequently have an equivalent cha- 

 racter in the direction of their curvatui'e. 



It is chiefly therefore when the ovule is I'educed to one, that 

 characters of much importance can be derived from the relative 

 position of the raphe to the placenta; and for the purposes of 

 arrangement, the positions of the anatropal ovule may be de- 

 scribed under the following variations, each of them including 

 also some instances in which the ovules are two, or three, or 

 more numei'ous. 



1. Ovule pendulous with the raphe turned away from the 

 placenta. 



3. Ovule pendulous with the raphe lateral, so that it appears 

 as if it were turned sideways in the cell. 



3. Ovule pendulous with the raphe next the placenta. 



4. Ovule horizontal with the raphe on the upper surface. 



5. Ovule horizontal with the raphe lateral. 



6. Ovule horizontal with the raphe on the under surface. 



7. Ovule erect with the raphe next the placenta. 



8. Ovule erect with the raphe on one side, that is, neither in 

 apposition with the placenta, nor yet turned directly away 

 from it. 



9. Ovule erect with the raphe turned away from the placenta. 



1. Ovule pendulous with the raphe turned aivay from the pla- 

 centa. This character was first observed by Mr. Brown in Euo- 

 mjmus, and subsequently by Dr. Schleiden in Ranunculacese 

 (Annals of Natural History, vol. v. p. 164), who, referring to 

 Mr. Brown's researches, remarks : " As far as I am aware, no one 

 has profited by his inquiries in order to solve similar anomalies 

 which obscure the clear principles of affinity," and adds some 

 further observations, describing it as " ovulum spurie pendulum 

 anatropum raphe avei'sa." 



The researches of Dr. Schleiden have already shown that in 

 the Typhaccse the raphe is averse, and as the Ranunculacese so 

 nearly approach Endogens, it might be supposed that it would 

 be of frecjuent if not constant occurrence in this class ; and I ara 

 able to add that in Chamcedorea elegans, although the ovule is 

 not completely pendulous, the raphe is next the dorsum of the 

 cell ; that in Potamogeton the ovule shows a decided tendency to 

 it in the direction of its curvature; and that the numerous 

 ovules of Aracese also show a tendency to it by the raphe being 

 frequently on the upper surface. There are, however, apparent 

 exceptions afterwards particularly alluded to. 



In Exogens it occurs more frequently as Endogens are ap- 

 proached, which the following enumeration will show : — 1. Ne- 



