PAST HISTORIES OF PLANT FAMILIES 



95 



rows by a normal cambium (see p. 66), and the trachea; 

 so formed had characteristic rows of bordered pits (see 

 fig. 62b). The wood comes nearer to that of the living 

 Araucarias than any other, and indeed the numerous 

 pieces of fossil wood of this type which are known from 

 all the geological periods are called Arattcarioxylon} A 

 double strand goes out from the main mass of wood, 

 which afterwards divides and subdivides to provide the 

 numerous bundles of the leaf. 



In the case of these fossils we are 

 fortunate enough to have the fructifica- 

 tions, both male and female, in a good 

 state of preservation. As in other 

 Gymnosperms, the male and female, 

 ■cones are separate, but they differed 

 Jess from each other in their arrange- 

 ment than do those of any of the living 

 types hitherto mentioned. They can 

 hardly be described as true cones, 

 though they had something of that 

 nature; the seeds seem to be borne on 

 special short stems, round which are Fig.63.— castofHoUow 

 also sterile scales. In the seed and ^'^ °f Cordaites, the 



^1 -^ • 1 1 1 /-> constrictions correspond- 



the way it is borne perhaps the Cor- ing to discs of solid tissue 

 •daitese may be compared more nearly across the cavity 

 with the Taxeae than with the other 

 groups. A seed, not yet ripe, is shown in slightly dia- 

 grammatic form in fig. 64, where the essential details 

 •are illustrated. The seeds of this family sometimes 

 reached a considerable size, and had a fleshy layer 

 ^vhich was thick in comparison with the stone, and ex- 

 ternally comparable with a cherry — though, of course, of 

 very diff^erent nature in reality, for Cordaites, like Taxus, 

 is a Gymnosperm, with simple naked seeds, while a 

 cherry is the fruit of an Angiosperm. 



' The addition of -oxylon to the generic name of any living type indicates that we 

 ■are dealing with a fossil which closely resembles the living type so far as we have 

 information from the petrified material. 



