142 THE MEDALS OF CREATION. Cuap. VI. 
jeune, fixé & Vextrémité d'un rameau.”* As it is only in 
their young state that the spikes are found attached to the — 
branches, it is probable they were shed as soon as they 
arrived at maturity. 
Triplosporite—Additional light has recently been thrown 
on the structure of the Lepidostrobi, by Dr. Robert Brown’s 
examination of a silicified specimen of the upper part of a 
strobilus, in which the internal organization is beautifully 
displayed. The reader specially interested in this depart- 
ment of fossil botany should refer to the original memoir 
by the illustrious President of the Linnean Society, with 
the accompanying plates that admirably exhibit the micro- 
scopic analysis of the structure of this remarkable fossil ; 
a slice of which was shown me some years since by the late 
Marquis of Northampton.t The external surface of the 
specimen is covered with hexagonal areolz ; the transverse 
sections exhibit the appearance of the bractese and sporangia. 
The strobilus is formed of a central axis of relatively small 
diameter, from which proceed bractez, about thirteen in 
number, that are densely approximated, and much imbri- 
cated ; and of an equal number of sporangia, filled with 
innumerable microscopic sporules, originally connected in 
threes. This triple composition of sporules (which differs 
from the constant quadruple union in the tribes of existing 
plants presumed to be most nearly allied to the fossil, 
namely the Ophioglossew and Lycopodiacce) is expressed by 
the name 7J'riplosporite, adopted by Dr. Brown to indicate 
this peculiarity of structure, and the class or primary divi- 
sion to which the original plant is supposed to belong. t 
* Hist. Vég. Foss. tom. ii. p. 47. 
+ The specimen brought to England was but two inches of the 
upper end of the cone; it was purchased conjointly by Lord North- 
ampton, Dr. Brown, and the British Museum, for 307. ! 
+ See Trans. Linnean Society of London, vol. xx. p. 469. 
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