Chambers's encyclopaedia; a dictionary of universal knowledge . leaves. The form of these seal like scars isvery variable, but they are all so arranged thatthe scars of each horizontal row are jilaced in theintervals between the scars of the mws immedi-ately above and below. The thick dichotomousbranches of the tree were clotlied with long grass-like leaves. The fruit is still unknown, somebotanists suppositig that Sigillaria hail cones likethose of lycojiods, while others think it probablethat the fruit resembled that of yew trees. Thestructure of the stem is peculiar : the externalrind or co
Chambers's encyclopaedia; a dictionary of universal knowledge . leaves. The form of these seal like scars isvery variable, but they are all so arranged thatthe scars of each horizontal row are jilaced in theintervals between the scars of the mws immedi-ately above and below. The thick dichotomousbranches of the tree were clotlied with long grass-like leaves. The fruit is still unknown, somebotanists suppositig that Sigillaria hail cones likethose of lycojiods, while others think it probablethat the fruit resembled that of yew trees. Thestructure of the stem is peculiar : the externalrind or coat is hard, beneath that is a great thick-ness of cellular tissue traversed by rope like llbres forming an inner bark, whili in the centreis a comparatively small lirm woody axis. jheroots usually start fiom the stem in four mainbranches, which divide dichotomously several times,and then extend for long distances like gieatcylindrical cables, which. Sir W. Hawson c(uisiders,were intended to anchor the tree firmly in soft and SIGISMDND SIGNALLING 443. maisliy triound. Cvlinilrical rootlets |>ioceeileilfiDMi these lonj: calilelike roots in a ref;|)iral manner, anil when they decayed they leftrounde<l soars. These roots were formerly sup-posed to he a distinct species till stems of Sigillanawere found with Stigmariau roots attached. The stem of Sigilaria is not often so well pre-served as to show any structure, or even its cylindri-cal form. It generally oecui-s ;vs a douhle layer ofcoal exhihitinj; on the outersurfaces the scars j)ro<hiccilby the bases of the from the fact thatmost coal-seams are underlaiilby what appear to be oMsoils or unilerclays, which arecrowded with roots, it wouhlseem that Sigillarijp, andprobably other trees with Sti;;-maria-roots, enter very lar^elyinto the formation of manycoal-seams. Some of the moreimpure coals, which are inter-laminated witli shale, &c.,consist principally of the tlat-tened stems of Sij^il
Size: 881px × 2836px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1900, bookpublisherlondo, bookyear1901
