1021. Vasculares, Phï¾µnogamous, or Cotyledonous, plants, are also separated into two great classes called Endogens or Monocotyledons, and Exogens or Dicotyledons, both which are distinguished as accurately by their obvious physical structure as they are by the minute and obscure peculiarities of the seed. They are all formed with cellular tissue, woody fibre, and spiral vessels (fig. 239.), and their leaves are traversed by veins; the last character is sufficient for practical purposes, if it is remembered that they also bear perfect flowers (that is, flowers furnished either with stamens, or pistils, or both), which will always prevent their being confounded with the highest tribes of Cellulares.
