Mr. J. Miers on Ephedra. 25 1 



which are found in Gnetum and Welwitschia. The tubillus, as 

 above stated, is a prolongation of the outer integument ; the red 

 fleshy gland is attached to and closes the mouth of the inner 

 integument. To a small point in the centre of this gland is 

 attached the white cylindrical and tubular suspensor, hemi- 

 spherical at its apex, the lower extremity of which descends 

 upon and adheres firmly to the upper part of the albumen, thus 

 forming a kind of white cap upon it for a quarter of its length. 

 This suspensor is capable of considerable extension ; and when 

 cut open along one side and examined under the microscope, 

 it is found to consist of a loose mass of condensed and extremely 

 fine flocculent tissue, confusedly huddled together like paper- 

 pulp, without the slightest trace of any of the coiled filaments 

 seen in Welivitschia and Gnetum, or any vessels whatever. The 

 albuminous mass is just the length of the embryo, and does not 

 extend over the summit of the radicle, which is quite naked 

 within the hollow cylinder, but it disappears gradually, and 

 becomes lost in the flocculent substance of the suspensor, be- 

 coming at last so far attenuated as to disappear in the form of 

 separate granular cells. From these facts we may infer that 

 this suspensor is only a portion of the amniotic body which has 

 not been obliterated, or in which albuminous grains have not 

 been deposited — a condition of development clearly indicated by 

 the acute sagacity of the late Mr. Uobert Brown*. 



AVe ought not, therefore, to attach much importance either to 

 the mere circumstance of a suspensor as a proof of the close 

 alliance of the Gnetacece with the Conifera and Cycadacece, seeing 

 that it is always diversified in the several genera, and difierent 

 from that structure in those families — or to the occasional pre- 

 sence of filaments bearing sterile embryo-sacs, for these never 

 occur in Ephedra, and not always in Gnetum — or to the exist- 

 ence of disciform dotted vessels in the wood, for they are found 

 only in Gnetum. These are only partial coincidences, and con- 

 sequently of little value in comparison with the strong evidence 

 showing a far more advanced perfection of floral structure in the 

 GnetacecE, and pointing to a much higher position in the system. 

 Other analogies remain to be discovered before this point can be 



* " In other cases the albumen is formed by the deposition of granulated 

 matter in the cells of the nucleus. In some of these cases, the membrane 

 of the amnios seems to be persistent, forming, even in the ripe seed, a 

 proper coat for the embrjo, the original attachment of whose radicle to 

 the apex of this coat may also continue." (Gen. Rem. p. 5/.) This view 

 applies as well to the origin of the vitellus in many seeds as to the peculiar 

 development existing in Ephedra ; and it is probable that future researches 

 may show the existence of an analogous development in other cases, and 

 may lead to a knowledge of the true affinities of the Gnetacece, which we 

 have yet to learu. 



17* 



