50 - Remarks on the Natural order Cycadea. 
in the structure of the seeds themselves, having the same integu- 
ments, the same foramina in the ovula and micropyle in the mature 
seed, with only such slight deviations in structure as might be ex- 
pected from the peculiar economy of these orders. 
In a paper read before the ‘“ British Association for the Advance- 
ment of Science,” at the fourth meeting, held at Edinburgh in 1834, 
Mr. Brown has adduced a new point of analogy between Conifere 
and Cycadez, in the tendency which exists in both these orders to 
the production of a ‘‘plurality of embryos” in the same nucleus. 
Occasional examples of this plurality were not unknown in other 
plants, but it was only in Cycadew that any constancy in this partic- 
ular had been observed. Mr. Brown’s recent investigations, how- 
ever, have demonstrated not only the general occurrence of this plu- 
rality of embryos in many Pines, bette also that a regular arrange- 
ment of these embryos within the nucleus takes place with much 
uniformity in both these families.* 
resemblance in inflorescence, fructification, and seed, are not 
the only points of agreement between Cycadew and Conifere. The 
simple cylindrical stem of the former, which resembles outwardly the 
trunk of the Palms, (a monocotyledonous order,) has been shown 
by M. Brongniart to be decidedly exogenous in stracture—probably 
only growing in the form of a simple trunk, in consequence of the 
non-development of the axillary buds. The leaves of both the Cy- 
cas and the Fir tribes, as Prof. Lindley remarks, have the same par- 
allel arrangement of veins, and both tribes exhibit a marked similar- 
ity in the fewness of their spiral vessels. Cycadee and Conifere 
still farther agree in a character lately discovered, as unique as it is 
important, and which alone would establish the fact of a strong affin- 
ity existing between the two orders; namely, the singular perfora- 
tions in, or rather globules adherent to, the fibres of their wood, to 
which there exists nothing analogous in the structure of any other 
tribe of plants.t 
* Since writing this paper, a work has reached us, containing details of some re- 
markable experiments and investigations, roe te y Corda, on the impregnation of 
plants, conducted with that accuracy and m cones so eminently characteristic 
ef the Germans, which tends to elucidate thie hitherto obscure portion of structu- 
tal botany. Corda’s experiments were made upon plants of the order Coniferey 
and the results are-highly curious. Dr. Gray has lately read before the Lyceum 
of Natural History of New York a translation of Corda’s memoir, which will 
Peeeh soon be published. (See Vol. XXXI, p-317.—Ep. 
So permanent is this characteristic, that geologists have recently through it 
identified Coniferous wood, which has been imbedded in the coal st ata for Cine 
