90 Mr, J. Miers on the Tribe Colletiese, 



instance I traced tlie existence of spiral vessels for more than 

 half the length of this cord ; in another they were visible nearly 

 as far as the foramen, but the dorsal cord was too opake to 

 allow them to be detected, although their presence there cannot 

 be doubted. The stipitate funicle was about a quarter of the 

 length of the primine, and was covered with a number of elon- 

 gated transparent cells, apparently in progress of extension, in 

 the manner observed by Brongniart, as above quoted; and to 

 their growth and expansion we may probably look for the origin 

 of the crustaceous coating of the seed. 



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 Brongniai-t, 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 production 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 



