40 Mr. J. Miers on the Tricuspidarieae. 



logons organization is observable in the Sloanece^ the seeds of 

 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 Tricuspidariece. 



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 Glusia 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 argument, in the instance of Aristotelian 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 instance f) 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 bony 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, xxii. 80, tab. 19. figs. 56-69; Contrib. Bot. i. 219; Ann. 

 Nat. Hist. ser. 8. i. p. 276. f Be Fruct. ii. 271. 



