CONTRIBUTIONS TO BOTANY. 
139 
Dr. Lindley (in 1836) * placed the Gnetacea among Gymno- 
sperms, next to Cijcadacea and Coniferce, but at the same time 
confessed that, having examined dried seeds of Gnetum, he felt 
inclined to favour the view of Blume, whose opinion he quoted 
at length, showing that the Gnetacece possess a far higher degree 
of organization, tending to a much nearer approach to Casuarina 
than to either Coniferce or Cycadacece. 
Endlicher (in 1837) f arranged the Gnetacece in his class 
Coniferce, after Taxinece, and, although preferring this position, 
he admitted their approach to Casuarina through Ephedra, on the 
one hand, on account of its aphyllous habit and the structure of 
its female flowers, and to Chloranthacece, on the other, through 
Gnetum, because of its fully- developed leaves. 
Meyer (in 1846)J published a monograph of Ephedra, which 
he prefaced by an inquiry into the nature of the flowering parts 
and seminal integuments in Gnetacece : he there conflrmed 
Brownes later view of the origin of the tubillus, which he showed 
to be a mere elongation of the micropyle of the inner integument ; 
but he adopted the view of Richard in calling the pericarpial 
covering of the frait an “ involucellum,” although he considered 
it rather in the nature of a perigonium : he there called the 
entire fruit a pseudo-nucula.^^ 
Dr. Lindley (in 1846) § followed his previous view of the posi- 
tion of the Gnetacece among Gymnosperms ; but he adopted the 
notion of Griffiths in respect to the pericarpial covering of the 
seed, which he regarded as one of its proper seminal integu- 
ments, adding, “ there can be no doubt that in reality Gnetum 
is as truly naked-seeded as conifers themselves.^^ 
A very interesting posthumous memoir of the late INIr. Griffiths 
on the structure and development of the ovule of Gnetum was 
read before the Linnean Society in 1859 |1, although a portion 
of the same appeared (in 1846) in the fii’st edition of Lindley^s 
‘ Vegetable Kingdom ’ (the original memoir bearing the date of 
August 1835)^. This memoir endeavoured to prove that the 
ovule of Gnetum is naked, that is to say, not contained in a 
carpel, but enveloped in three or four distinct proper integu- 
ments, which, being open at the summit, allow the direct action 
of the pollen upon the nucleus. That ingenious botanist con- 
cluded, from the facts he adduced, that the Gnetacece are truly 
gymnospermous, and more nearly allied to Cycadacece than to 
Coniferce. 
Lastly, Agardh (in 1858),** following the opinion of Richard, 
* Introd. Bot. p. 311. t Gen. Plant, p. 262. 
J Mem. Acad. St. Petersb. v. pp. 35-108. 8 tab. 
§ Veg. Kingdom, p. 232. || Linn. Trans, xxii. p. 299, 
^ Veg. Kingd. p. 233. ** Theor. Syst. p. 113. 
T 2 
