CONTRIBUTIONS TO BOTANY. 
245 
I have noticed precisely the same facts in Rhamnus Alaternus, 
where the raphe is strictly dorsal, as in R. catharticus ; in one 
instance I observed that the coats of the ovule had become quite 
opake, the mouth of the primine being closed by a tumid expan- 
sion over it, and that this expansion embraced the long funicle, 
which had nearly disappeared : we may thus account for the total 
absence of any funicle in the ripe seed. I will not aver that this 
evidence is complete ; but the disappearance of the funicle and 
the production of a distinct extraneous coating over the ovule, 
to whatever cause they may be owing, are most evident facts. 
There is much probability that this crustaceous coating derives 
its origin from the growth and expansion of the funicular sup- 
port, — a growth first noticed by Brongniart, and apparently 
confirmed by what I have seen and recorded above. To this 
cause we may attribute the production of the vacant space that 
exists in the seed between the membranaceous integuments and 
the lower portion of the crustaceous ■ coating, and also the 
appearance of the suspensor-like thread in which the base of the 
two membranaceous integuments terminates; for Brongniart 
recounts that, after impregnation, he found the mouth of the 
secundine embraced by the neck of the primine, just as I have 
described the appearance in the basal extremity of the two inner 
integuments of the seed of Zizyphus. 
There exists in some instances yet another pi’oduction over 
the seed, still more external than the crustaceous coating, the 
mention of which I have delayed till now. This expansion, 
which seems to proceed from the placentary point of attachment 
of the funicle, shows itself in a rudimentary state in Zizyphus, 
as I have before described it, under the form of a small free cup 
with a crenulated margin, which remains fixed to the pericarp, 
and in which the sessile seed reposes ; this seems to be a con- 
stant feature in that genus. In Phylica and its congeners the 
seed is affixed in a stipitate cup that remains attached to it ; 
this is fleshy, generally four-toothed on the margin, but in one 
genus is deeply cleft into ten radiating lobes. 
In Alphitonia it assumes its fullest development, appearing as 
a thin, dark-coloured, brittle, submembranaceous, loose enve- 
lope, open at the top and sometimes also along the dorsal face ; 
but in all cases the margins of this opening overlap each other, 
and thus entirely conceal the seed. This was first described by 
Fenzl*, who calls it a brittle testa, covering the smooth carti- 
laginous endopleura.” Endlicherf, on the other hand, desig- 
nates it as an “arillus, covering a smooth corneous testa.'’ 
Dr. Asa GrayJ, speaking of this tunic, '^doubts if this mem- 
* Plant. Hugel, p. 20, sub Colubrina excelsa. 
t Gen. Plant, no. 5712. J Bot. Explor. Exped. Un. St. p. 2/8. 
