40 Mr. J. Miers on the Tricuspidarieee. 
logous organization is observable in the Sloanee, the seeds ot 
which have a similar red-coloured fleshy covering, which has 
been designated by some authors an arillus ; the ‘second tunic 
is osseous, and broadly truncated at its base by a large orbi- 
cular chalaza; but this wants the hollow chamber below it, 
which forms a characteristic feature in the Zr tcuspidariee. 
In regard to the nature of these seminal envelopes, the outer 
coat may be regarded as an arilline, analogous to a similar 
tunic which I formerly described covering the osseous coat in 
the seeds of Clusia and Magnolia*. Upon the nature and 
origin of these integuments I then endeavoured to offer an ex- 
planation, which was contested by others, who maintained 
that in these cases the outer fleshy covering is merely the epi- 
dermis of the bony coat, both being elicited by the growth of 
one single tunic, the primine of the ovule. There is a bar to 
such an areument, in the instance of Aréstotelia, in the ex- 
istence of the singular appendage upon the outer fleshy coat, 
resulting from the duplicature of that integument, which could 
not occur if it were merely an epidermis. “By those who have 
not studied the subject, the origin of this appendage might be 
attributed to a fungous enlargement of the funicle (as Gaertner 
supposed in an analogous instancet) or to an expansion of the 
chalaza; but a more careful examination will show that it 
is too remote from the latter and from the hilum to admit 
of such a supposition. Whatever be its origin, this outer tunic 
appears to be an integument wholly independent of the bony 
shell, consisting of its reticulated epiderm, a fleshy mesoderm 
replete with resinous cells, and an endoderm in the form of a 
white, opaque, reticulated cuticle, separable from the shell, 
the chord of the raphe being found within its substance. 
The fact that this fleshy tunic and bony shell are two dis- 
tinct integuments is shown by an examination of the unim- 
pregnated ovules in the abortive cells of Aristotelia: here, 
with the ovules grown to the length of half a line, I have 
succeeded, by means of a longitudinal section, in actually sepa- 
rating them. The tunics, which, if fertilized, would have 
grown into the fleshy coating and hony shell, are then seen as 
two distinct, thin, membranaceous integuments, easily separa- 
ble at this stage, ’ the second being a little shorter and more 
pointed than the first or outer one, the third integument, en- 
closing the rudimentary nucleus, being still shorter than the 
others. It is worthy of notice that at this stage the outer in- 
tegument exhibits the peculiar appendage or duplicature so 
conspicuous in the ripe seed. 
* Linn. Trans. xxi. 89, tab. 19. figs. 56-59; Contrib. Bot. i. 219; Ann. 
Nat. Hist. ser. 3.1. p. 2 276. + De Fruct, ii, 271. 
