. Evolution of plants . number of stalkedovules are borne, intermingled with barren structure of the gynseceum is better made outin the mature specimens, where the flower hasbecome a fruit. The point to note here is thatthe arrangement of the organs in the fructifica-tion of the Mesozoic Bennettites is just the sameas in a typical Angiospermous flower—on theoutside the bracts, which might quite well becalled a perianth, then a ring of stamens, andfinally the female apparatus in the arrangement seems to have been general inBennettites and to have extended to some of itsal
. Evolution of plants . number of stalkedovules are borne, intermingled with barren structure of the gynseceum is better made outin the mature specimens, where the flower hasbecome a fruit. The point to note here is thatthe arrangement of the organs in the fructifica-tion of the Mesozoic Bennettites is just the sameas in a typical Angiospermous flower—on theoutside the bracts, which might quite well becalled a perianth, then a ring of stamens, andfinally the female apparatus in the arrangement seems to have been general inBennettites and to have extended to some of itsallies, though in other related plants the flowersare said to have been of separate sexes. In the more mature fructifications the stamenshave disappeared, leaving only a rim round thebase of the receptacle, to show where they wereinserted. One of the best examples of thefruiting stage is found in Bennettites Gibsonianus,the Luccombe Chine fossil; this plant was the 86 THE EVOLUTION OF PLANTS first to be discovered inbr. Fig. 10.—Bennettites Gibso-nianus. (A) Diagram of fruitin longitudinal section: (re)receptacle; (br) bracts; (s)stalked seeds, each contain-ing a dicotyledonous embryo;(p) sterile scales, with dilatedends forming the pericarp.(B) transverse section of aseed; (i) seed-coat; (n) re-mains of nucellus; (ct) thetwo cotyledons of the embryo,cut across. X about Scott, Studies. a fertile condition, andfrom this discovery ourknowledge of the Bennet-titese may be said to date,for though related plantshad been discoveredmuch earlier, their struc-ture was not understood. The fructifications areborne in exactly thesame way as those ofthe American species,and their structure isno doubt essentially thesame, only they happento have been fossilised ata later stage of develop-ment, when the flowerhad become a fruit. The bracts still enclosethe fruit, but the stamenshave gone, and the gyn-seceum has enlarged so asto fill up all the spacewithin the bracts (, a). The
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