[ M9 ] 
VII. Remarks gn the Examination of some Fossil Woods, which tend to eluci- 
date the Structure of certain Tissues in the recent Plant. By EpwiN Joun 
QUERETT, Esq., F.L.S. &c. 
Read March 18, 1845. 
AMONG the many disputed points in vegetable anatomy, few have excited 
more controversy than the structure of spiral vessels, and the markings on the 
woody fibres of plants belonging to the order Conifere. Having found in- 
stances of these structures in the fossil state which appear satisfactorily to ex- 
plain their nature, the following observations are offered to the notice of the 
Society. In doing so, it is not intended to enter into any detailed account of 
the minute anatomy of these parts, as it is generally known and already de- 
scribed in most botanical works. 
From the period of the discovery of spiral vessels in plants by Henshaw, in 
1661, up to the Jast quarter of a century, numerous have been the theories 
respecting their structure; the older vegetable anatomists, from the imper- 
fection of their microscopes, were led to form various opinions on these mi- 
nute organs, which have been recorded in works on vegetable anatomy. The 
true structure, by the aid of delicate manipulation and improved means of 
observation, had however, to most recent observers, appeared to be deter- 
mined; as it can be shown that these organs are composed of a cylinder of 
membrane closed at each end, in the interior of which are one or more fibres 
coiled spirally. This is a fact often to be seen in favourable dissections, and 
is decidedly manifest when the development of the fibre is watobed in the 
manner I have described in vol. i. of the ‘Transactions of the Microscopical 
Society; but another opinion has been entertained, that the fibres are coiled 
spirally on the exterior of the cylinder of membrane, instead of in its in- 
terior. j ia 
On examining lately a specimen of fossil wood, exhibiting the structure of 
