and on the Structure of the Seed in the Rhamnaceae. 89 



ing of the funicular support, and its subsequent extension over 

 the coats of the ovule, seemed to support. I now call attention 

 to this last-mentioned circumstance, because it may serve to 

 explain some essential points of structure in the seeds of the 

 Rhamnacea, and may enable us to trace the source of the external 

 tunic of the seed, which, on account of its crustaceous or cor- 

 neous texture, has been mistaken for the testa, but which is 

 evidently of a different nature and origin. 



I will also record some circumstances observed by me that 

 may tend to throw some additional light upon the nature of this 

 development. We very often find, in the fruits of Rhamnacecp, 

 that one of the carpels is sterile ; here generally the abortive 

 coccus grows nearly to its full size, but it is quite flattened, with 

 its line of dehiscence, as usual, along the middle of the ventral 

 face ; in such carpels we always meet with a persistent unim- 

 pregnated ovule, standing upon its long funicle. In Rhamnus 

 chlnroplionis, for example, the sterile coccus is orbicular, and 

 1^ line in diameter; the length of the ovule with its funicle is 

 ^ line ; it is erect ; the foramen of the primine is distinctly open, 

 and points downward, the tunic itself showing yet no indication 

 of any plicature ; the secundine, seen through the primine is 

 shorter and smaller; and the nucleus is much narrowed, being 

 scarcely half the length of the primine; while the chalaza is 

 clearly visible in the summit, and also the thick distinct opake 

 line of the raphe extending into it from the funicle. The posi- 

 tion of the raphe, in this ovule, exactly corresponds with its 

 place and direction in the ripe seed, showing, as I have before 

 indicated (p. 81), that its situation, which has been considered 

 abnormal in the seed, is not due to any twisting of the funicle, 

 or to any disturbance caused by the subsequent plicature of the 

 different parts of the ovule ; and this we find to be further proved 

 by the presence of the " telje conductrices " immediately beneath 

 the foramen of the primine, which would not happen had the 

 ovule been forced round into this position by the torsion of its 

 umbilical cord. I have found, in the several instances examined, 

 the main line of the raphe and funicle constantly in one and the 

 same position upon the dorsal face, everted more than the quarter 

 of a circle (140°) from the point of zero, starting from the axial 

 line of the fruit : from the chalazal summit, and down the con- 

 trary or ventral face of the primine, is seen a second cord, cor- 

 responding in position with the ventral raphe of the seed, and 

 running from the summit to the mouth of the tunic. In one 



I'ovule," — an opinion which he soon renounced after his subsequent im- 

 portant investigations into the growth of the ovule: Ann. Sc. Nat. xii. 

 ehap. p. 242. 



Ann. ^ Mag. N. Hist. Ser. 3. JV. v. 7 



