CHAP. II. 



OVARY. 



178 



128 

 a c 



L^l 



if a, h in Jig. 128. represents the 

 side of one carpel and c, d tliat 

 of another, the dissepiment «, c, 

 Z», d formed by this union will 

 have precisely the same direction 

 as that of the carpels, and can 

 never acquire any other ; and 

 / b d h the same would be true of the 



sides e,y*andy, A, if they formed themselves into dissepiments 

 by uniting with other carpels: consequently a partition in any 

 cell in the direction of z, k could not be a dissepiment, but 

 would be of a different nature. 



"2. They are uniformly equal in number 

 to the carpels out ofiohich the pistillum is 

 formed. — Suppose the triangle A, B, C 

 represented a ti'ansverse section of an 

 ovary formed by the union of three car- 

 pels 0, 0, ; then d, e, f would be the 

 dissepiments, and could not be either 

 more or less in number. 



3. They proceed directly from the pla- 

 cent<B. — As the placenta is the margin 

 of the carpellary leaf, and as the dissepiment is the side of the 

 carpellary leaf, it is evident that a dissepiment cannot exist 

 apart from the placenta. Hence, when any partition exists in 

 an ovary and is not connected with the placenta, it follows 

 that such a partition is not a dissepiment, however much it 

 may otherwise resemble one. 



4. They are alternate with placentce, formed by the cohesion 

 A d B of the margins of the same carpel^ and op- 



posite to placentce^ formed by the cohesion 

 of the contiguous margins of different car- 

 pels. — Let the triangle A, B, C repre- 

 sent a transverse section of a three-celled 

 ovary of which d^ e, f are the dissepi- 

 ments : the dissepiments d and e will 

 alternate with the placentae m, g, both 

 belonging to the cai-pel A ; but the dis- 



