STRUCTURE.] THEIE NORMAL POSITION, ETC. 



379 



will have precisely the same direction as that of the carpels, 

 and can never acquire any other ; and the same would be true 

 of the sides e f and g h, if they formed themselves into dis- 

 sepiments by uniting with other carpels : consequently a 

 partition in any cell in the direction of i k could not be a dis- 

 sepiment, but would be of a different nature. 



2. They are uniformly equal in number to the carpels out of 

 which the pistillum is formed. Suppose the triangle ABC 



represented a transverse section of an ovary formed by the 

 union of three carpels o, o } o ; then d, e, f would be the 

 dissepiments, and could not be either more or fewer in 

 number. 



3. They proceed directly from the placenta, when that part 

 originates in the margin of the carpel. As the placenta is 

 then the margin of the carpellary leaf, and as the dissepiment 

 is the side of the carpellary leaf, it is evident that in such a 

 case a dissepiment cannot exist apart from the placenta. 

 Hence, when any partition exists in an ovary and is not 

 connected with the marginal placenta, it follows that such a 

 partition is not a dissepiment, however much it may otherwise 

 resemble one. 



4. They are alternate with placenta formed by the cohesion 

 of the margins of the same carpel, and opposite to placentce 

 formed by the cohesion of the contiguous margins of different 

 carpels. Let the triangle ABC represent a transverse section 

 of a three-celled ovary of which d, e, f are the dissepiments : 

 the dissepiments d and e will alternate with the placentae 

 m, g, both belonging to the carpel A ; but the dissepiment d 



