OF TTIK RAPHE IN SEEDS. 99 



the testa, and which bj' pressure leaves a corresponding groove on the surface of the 

 albumen, is singukir in its form, on accoimt of its retroversion in the manner I have 

 detailed, both hiire and in my Monograph of tlie genus. Its nature does not appear to 

 have occurred to Mr. Thwaites, for he describes it merely as " a whitish raised line, which 

 is very conspicuous on the outside of the seed, passing quite round it length\vise, and 

 consisting of a fillet of spiral vessels lying between the two thin coats or layers of the 

 testa." The nature of this fillet is soon ascertained by tracing it to its origin, and I have 

 again referred to the parts of my two analyses which I have preserved, and these confirm 

 my previous inference. As its form and position involve other considerations of some im- 

 portance, it is desirable to describe it more in detail. On examining the putamen, which 

 is the lignifled endocarp of the fruit, we find it of an oval form, slightly flattened on one 

 side, along which is observed a longitudinal groove, in which is imbedded a thick cord or 

 bundle of fibres, which is easily raised from the channel, and is found to penetrate an 

 apertiu'e in the upper extremity of the groove : some fibres proceeding from the stigma 

 here join it, and the cord now reduced to a thread, after its passage through that aper- 

 ture into the cell, becomes attached to the testa of the seed, on a small protuberance 

 near its apex ; it then assumes the features of a prominent line iipon it, and descends 

 along one angle of the dorsal face of the seed, to near its base, then curves round this, 

 and ascends along the other angle of the same face, to a hollow in the summit, beneath 

 the apical protviberance just mentioned, where it disappears, describing in its course a 

 horse-shoe, or rather an oval curve : and this is the " whitish raised line " described by 

 Mr. Thwaites. The nourishing vessels are thus distinctly apparent throughout their 

 entire course, from the external base of the putamen to the vanishing point of the thread 

 just described, in one continuous line : the external portion of this cord is evidently the 

 placentary axis of the dissepiment of the normal bilocular ovarium, for in the 2-celled 

 and 2-seeded fruit which I have mentioned, where the seeds were separated by a distinct 

 partition, this same cord was seen imbedded in the line of its axis, and became furcated 

 on arriving at the simimit, each branch passing through a double aperture rato the two 

 cells, where it attached itself to the apex of each seed, and continued in its course as the 

 "whitish raised line" of Mr. Thwaites: this thi'ead therefore bears the character of a 

 raphe ; but as its form is very peculiar, it is well to compare it with the same organ in 

 other genera of this family. 



The development of the seed in Sfeuioniirits is precisely similar to that in Fcnnantkt, as 

 I have elsewhere shown, agreeing even in the same relative size, shape, and position of 

 the embryo, differing only in the singular extension of the raphe, and the presence of a 

 large vacuity in the centre of the albumen, lined with thin pellicular plates. In Fennanfift, 

 as in other genera of the Icacinacece, the raphe originates as in Stemomtrtis ; but its 

 course is along the middle of the dorsal face, and it loses itself at the opposite or coty- 

 ledonary extremity of the testa, according to the law of anatropal development : in the 

 latter genus, contrary to general rule, the descent of the raphe is along one side of the 

 seed, and, after crossing the lower part, it ascends up the other side, to near the point 

 from which it started, and is lost in the integument, close to the extremity of the radicle : 

 the raphe in this course, which is always inclined a little towards the dorsal face, leaves 



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