This plan of observation was discontinued after the term-day of February, and the simultaneous mode changed by new instructions from Professor Lloyd.
The medical officers of the expedition, whose judicious measures had been so successful in preventing even the least appearance of disease in any of our crew, having fortunately no professional calls upon their time, visited the more distant parts of the colony, collecting information, and specimens of the geological character of the country, as well as its other natural productions. Amongst the more interesting of these, and which claims the earliest attention of geologists visiting YanDiemen's Land, is the valley of fossil trees, many of which are beautifully and perfectly opalized, and are found imbedded in porous and scoriaceous basalt, and of which Count Strzelecki remarks, in his admirable physical description of this country,—"Nowhere to my knowledge is the aspect of fossil wood more magnificent than in the Derwent Valley, and nowhere is the original structure of the tree better preserved; while the outside presents a homogeneous and a hard glossy surface, variegated with coloured stripes, like a barked pine; the interior, composed of distinct concentric layers, apparently compact and homogeneous, may be nevertheless separated into longitudinal fibres, which are susceptible of subdivision into almost hair-like filaments."
I had an opportunity of visiting these very