300 MR W. GRIFFITH ON THE GENUS GNETUM. 
Tuıs paper owes its existence to Dr. Lindley, who with his usual kindness pointed out to : : 
me this, among several other genera, as an interesting subject for study. In glancing over | 
the history of this genus, we find that very little additional information had been acquired — 
upon its structure from the period of its original publication by Linnæus, from whose . 
character all the subsequent ones have been more or less. derived, until the appearance of — 
Dr. Brown's: Memoir relative to the character and description of Kingia appended to 
King's Voyage*. Previous to the appearance of this important publication, all botanists | 
who had noticed this genus had ascribed to the female flower the ordinary structure, It — 
‚will hereafter be seen that all those who have formed this opinion of the structure of . 
Gnetum have examined the female flowers at a rather late period. Tr 
Dr. Brown, in the Memoir above referred to, p. 23, gives it as his opinion, that in 
Cycadee, Conifere, Ephedra, and Gnetum, the ovarium is either altogether wanting, or — 
so imperfectly formed that the ovulum itself becomes directly exposed to the action of the . : 
pollen. He further states.that “the similarity of the female flower in Cycadeæ and — 
Conifere to the ovulum of other phænogamous plants, as I have described it, is indeed 
sufficiently obvious to render the opinion here advanced not altogether improbable; but : 
the proof of its correctness must chiefly rest on a resemblance, in every essential point, - 
being established between the inner body in the supposed female flower in these tribes, 
and the nucleus of the ovulum in ordinary structures, not only in the early stage, but 
also in the whole series of changes consequent to fecundation. Now, as far as I have yet 
examined, there is nearly a complete agreement in all these respects.” 
After repeated examinations of Cycas, Gnetum, and Agathis, in their growing states, it — 3 
may perhaps not be considered presumptuous in me to add my feeble testimony to the — å 
extreme accuracy of this statement of Dr. Brown t. E 0 
Professor Lindley, in his valuable Introduction to the Natural System of Botany, — 
while he admits to the fullest extent Dr. Brown’s notions on Cycadeæ and Conifere, : 
appears to entertain the old opinion as to the structure of Gnetum; and here it is again — 
evident that this truly philosophical botanist has only examined somewhat advanced | 
female flowers. I find, however, that in his remarks on Garrya (Bot. Register, vol. vi. — 
new series, t. 1686), this author has adopted the opinion of Dr. Brown, and speaks of E 
Gnetaceæ, a naked-seeded order. — — d 
: Having thus briefly alluded to the opinions entertained on the structure of this 
singular genus, I shall now proceed to the consideration of the structure and develop- 
ment of the female flower, which consists of a single naked ovulum. B 
At a period long before the exsertion of the anthers, the ovula, which lie upon the male — 
flowers, are generally of an oblong form, and consist of a central cellular solid body, : ; 
enclosed in two envelopes. The outermost of these is fibro-cellular, and divided longitudi- s 
nally on the upper face, or that nearest the axis, the fissure extending nearly to the base — 
of the ovulum?. The inner or second envelope is cellular, and is divided irregularly — 
* ls Meno 
Of this | oir I have seen only an 8vo copy, in the possession of Dr. Wallich. 
T At the same time, Dr Brown's observati : : 
; ; . t addi 
membrane, * (See Kingia, Apes rvations refer only to a period subsequent to the appearance of the 
? This division is perhaps similar to that which Dr. Brown states to take place in Dacrydium. 
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