IN THE CLUSIACEÆ, MAGNOLIACEÆ, ETC. 83 
and its connexion with the raphe, in the relative position in which the latter is found, 
have evidently escaped the observation of these eminent botanists, as they had previously 
done that of Gærtner; it is, however, important to attend to these distinctions, as they 
form essential and convincing elements in this inquiry. 
Still more recently a paper from Dr. Asa Gray has appeared in * Hooker's Kew Journal 
of Botany’ (vol. vii. p. 243), “On the Development and Structure of the Integument of 
of the Seed of Magnolia.” This was written in reply to my observations on the arilliform 
nature of the outer tunic, to which I have above referred. In that note, this accomplished 
botanist warmly defends his former opinion, which he maintains with great ingenuity and 
candour, but I find nothing there stated that disproves the conclusion of most botanists, 
regarding the nature of the several seminal tunics in question, which I have here 
endeavoured to confirm. If I had not been convinced that the issue admits of the most 
simple and demonstrative proof, I should not have presumed to contest the united 
authority of the distinguished American professor, and of the highly talented authors of 
the * Flora Indica,' whose opinions are entitled to especial consideration. 
. The argument that the scarlet external envelope cannot be an aril, because the latter 
* must needs have an opening at the top," stands upon very feeble ground. This was the 
definition of St. Hilaire, who classed the different forms of arilliform coatings under two 
denominations: 1. the true aril where the envelope has an opening in the top; 2. the 
false aril, where the coating that surrounds the testa is entire. Dr. Planchon, however, 
who ably defended and extended the views of his friend, in regard to the nature and 
origin of the aril,has shown that this definition does not hold good, and among other 
cases, he cites a species of Tetracera from Java, where the perfectly true aril forms an 
entire tunic. I need hardly refer to Gærtner, who also divides the aril into two kinds, 
the complete and the incomplete; notwithstanding that in some of the instances of the 
first kind, he has mistaken the endocarp for an aril; others, which he enumerates, possess 
a complete arilliform covering, among them Nephelium, which in this respect offers a 
good analogy with Magnolia. Another instance is still more remarkable, because it is 
recorded by Dr. A. Gray himself, in the same admirable work, and within a few pages of 
his description of Magnolia: it occurs among the Anonacee, figured in the genus Asimina, 
(plate 27) and described (p. 57) as entirely covering the testa, without the mention of any 
aperture in the apex. There is indeed no reason why an aril, which ". development 
from the placenta, may not form an entire coating, as well as the true integuments of 
the seed, originally cup-shaped processes. The argument of the inadmissibility of an aril, 
because it is not open at the top, therefore completely fails. 
In regard to the remaining arguments of Dr. A. Gray, I can only 
been demonstrated, that the nourishing vessels from the placenta, as he has figured them, 
only penetrate the primine of the ovule of Magnolia at the gangylode* ; they € = 
do not enter at the opposite extremity; but if we examine the ripe seed, we e 
repeat what has just 
* For the sake of demonstration I have here given the name of gangylode to that common point of A of a 
primine, secundine and tercine in the original base, now the summit of the inverted ovule, which afterwards form the 
diapyle of the testa, and the chalaza of the inner integument of the seed. = 
