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MANUAL OF BOTANY 



spurious except those which are formed by the union of the 

 walls of contiguous ovaries, and it occasionally happens that 

 such spurious dissepiments are formed in the course of growth, 

 by which the oyary acquires an irregular character. These 

 false dissepiments commonly arise from projections of the 

 placentas inwards ; less frequently by ingrowths from some other 

 parts of the walls of the ovaries. Some of these are hori- 

 zontal, and are called phragmata, as in Cassia fistula [fig. 

 417), where the ovai-y, after fertilisation, is divided by a 



Flg. 417. Fig. 418 



Fio. 4111. 



Fro. 420. 



/Vf/. 417. Vertical section of a portion of the mature 

 ovary of Cassia fistula, showing a numlDer of trans. 



verse spurious dissepiments (phragmata). Fig. 



■118. Vertical section of the ovary of the Wallflower. 

 ov. Ovules, each attached by a stalk to the placenta, 

 en. cl. Vertical spurious dissepiment called the re- 

 plum. Fig. 419. Transverse section of the lower 



part of tlie ovary of the Thorn-apple (Datura iStra- 

 tfwninm), showing that the ovary is here four-celled. 

 Fig. 420. Transverse section of the same ovary at its 

 upper part, showing tliat it is here two-esUed. 



number of transverse dissepiments, which are ingrowths from 

 its walls. Others are vertical, as in Cruciferous plants, where 

 the dissepiment, called a replum (fig. 418, cl), is formed from 

 the placentas. Another ease is that of Datura Stramonium, 

 where the ovary is formed of two carpels, and is hence normally 

 two-celled ; but, instead of remaining bilocular, it becomes four- 

 celled below {fig. 419) from the formation of a spurious vertical 

 dissepiment. This dissepiment does not extend to the top of 

 the ovary, so that the upper portion of the latter is only two- 

 celled {fig. 420). In the Gourd tribe {fig. 548), also, spurious 

 dissepiments appear to be formed in the ovary in a vertical 

 direction by projections from the placentas. In the Flax, 

 again {fig. 421, 6), spurious incomplete vertical dissepiments 

 are formed in the ovary by projections from the dorsal sutures, 



