46 GENERAL REMARKS ON THE 



The outer coat of the seed or caryopsis of Casuarina 

 consists of a very fine membrane, of which the terminal 

 wing is entirely composed ; between this membrane and 

 the crustaceous integument of the seed there exists a 

 stratum of spiral vessels, which Labillardiere, not having 

 distinctly seen, has described as an "integumentum arach- 

 noideum ;" and within the crustaceous integument there is 

 a thin proper membrane closely apphed to the embryo, 

 which the same author has entirely overlooked. The 

 existence of spiral vessels, particularly in such quantity, 

 and, as far as can be determined in the dried specimens, 

 unaccompanied by other vessels, is a structure at least very 

 unusual in the integuments of a seed or caryopsis, in w^hicli 

 they are very seldom at all visible, and have never, I believe, 

 been observed in such abundance as in this genus, in all 

 w^hose species they are equally obvious. 



CONIFERiE.' The structure of the female parts of 

 fructification in Coniferae having, till very lately, been so 

 little understood, and certain facts concerning it being 

 still unpubhshed, I shall prefix a few observations on this 

 subject to the remarks I have to offer on the Australian 

 part of the order. 



In the late essays of Mirbel and Schoubert on Conifer cb" 

 that part of the female fructification which had previously 

 been considered as the pistillum, having a perforated style, 

 is described as a peculiar organ enclosing the ovarium, and 

 in most cases also the stigma. This organ, wdiich they 

 have named cupula, they regard as more analogous to an 

 involucrum than to a perianthium, which, according to 

 them, also exists, cohering, how^ever, with the body of the 

 ovarium. Without absolutely adopting this latter part of 

 their statement, it appears to me that impregnation really 

 takes place in the manner these authors describe. Their 

 principal argument is derived from the genus Ephedra, in 

 which both the stigma and a considerable part of the style 

 project beyond this cupula, without cohering with its aper- 

 ture. In further confirmation of their opinion it may be 



* Ju8s. gen. 431. "^ Notw, bulletin des scien. 3, p. 73, 85, el 121. 



