STRUCTURE.] FALSE ARILS. 45 



between the aril and the funicle being marked by any 

 contraction. This expansion is again found still narrower 

 and less distinct from the umbilical cord in the genus 

 Serjania; and, lastly, in some species of Cardiospermum 

 (C. Halicacabum) we find nothing but the funicles thickened 

 at their top without any trace of a free edge, whilst in others, 

 with a less extended umbilical scar, a funicular expansion is 

 seen which can be nothing but a rudiment of the aril. In 

 these cases, of which I could furnish more in the same natural 

 order, care must be taken not to confound the free part of 

 the expansion of the umbilical cord, which alone is the aril, 

 with any expansion of the same cord which, being extended 

 over the seed, adheres to the testa, and which would only 

 cover the surface of the hilum. 



It is in consequence of inattention to this character of the 

 aril, viz., its non-adherence to the testa, that this name has been 

 given to the remarkable expansion of the top of the funicle 

 found in beans, peas, and other Leguminous plants, as well 

 as to umbilical scars when large and coloured, as in Cardio- 

 spermum, from which they have taken their generic name. 

 The term aril does not apply to the thin fleshy lobed plate 

 which, in Connarus and Omphalobium, is extended on the 

 surface of the seed from the beginning of the raphe to about 

 the middle of its length, and which is independent of the 

 umbilical cord and of the hilum, being a parenchymatous 

 layer of the testa to which it is intimately joined. 



Now that we have gone through the principal modifications 

 of the aril, it will be easy to recognise those appendages of 

 the seed which have been wrongly called by this name, and 

 which we shall next review in detail. 



C. Of the False Aril. If there is on seeds any envelope of 

 doubtful nature it is certainly that which we are now going 

 to notice ; exterior with respect to the proper integuments, 

 covering the exostome, and depending like the aril on the 

 umbilical cord, it is distinguished from the aril, by important 

 characters, and constitutes a very anomalous false aril. 

 Perhaps, indeed, the name of false testa would be more 

 applicable to it, in consequence of its crustaceous texture, 



