534 Carruthers — On Fossil Coniferous Fruits. 



granite during its progress througli the strata that envelop it. But 

 if this had been the case we should certainly expect to find the nests 

 not only more abimdant near the junction of the granite with the 

 stratified rocks, but indeed almost if not exclusively confined to that 

 area. They are not more characteristic, however, of one portion of 

 the granite than of another, but, as already remarked, are scattered 

 indiscriminately throughout. I am therefore forced to conclude that 

 the crystalline rocks described above have resulted from the alteration 

 in situ of certain bedded deposits. The occurrence of the " nests " 

 cannot be accounted for on any other theory. But the explanation 

 advanced is quite in keeping with the phenomena presented by the 

 rock -masses themselves ; as, for instance, their peculiar development 

 in and tendency to eat along the strike of felspathic greywackes in 

 preference to muddy shales — the sharp junction-line that separates 

 the granite from the latter, and on the contrary, the gradual passage 

 that is traceable from granular greywacke into granite. 



II. — 0?^ SOME Fossil Coniferous bruits. 



By "William Carruthers, F.LS., Botanical Department, British Museum, 



(PLATES XX. AND XXI.) 



IT was my intention to have devoted this paper to the Coniferous 

 Fruits found in Strata of Secondary age in Britain, reserving for 

 future examination, those belonging to the later periods, but in the 

 progress of my investigations I have found that, two remarkable cones, 

 which have hitherto been considered as belonging to the Glreensand, 

 are certainly Tertiary fossils ; and having placed them on the plates 

 which illustrate this paper, I shall include them in my descriptions. 



The existence of Conifers during the geological history of the 

 globe is determined by the occurrence of wood, fruits, and leaves in 

 the rocks of different periods. Leaves are very rare, and almost 

 always when alone are unsatisfactory evidence, as the forms of the 

 leaves, and their arrangement on the stem, are similar in many 

 Conifer ce- to what are found in other and very different orders of plants. 

 The fruits and wood are more frequent, and are also more satisfactory 

 indications of the organisms to which they belong. Coniferous wood 

 exhibits a peculiar structure which cannot be mistaken, and which is 

 found in no other set of plants. This structure is the absence of any 

 dotted ducts in the concentric layers of wood, and the presence of 

 discs in the lateral walls of the woody fibre. The disc-bearing 

 tissue alone, is not sufficient to determine a fragment of wood to be 

 coniferous, as this structure is found also in the wood of several 

 Magnoliacecd, but the two characters together are found in no known 

 wood except that of Conifercs proper, and their gymnospermatous 

 allies. The fruits, again, are peculiar to this order, for while cones are 

 found in some Proteaceoe, the internal structure is very different, the 

 seeds being contained in true seed-vessels, and rising from the axis 

 in the axils of the scales or bracts; the pseudo-cones produced 

 in diseased branches in some other plants can easily be distinguished, 

 as they never contain seeds. True Coniferous cones have been 



