CONSTITUTION OF THE ANIMAL AND PLANT KINGDOMS. 57 



developed. Such a state of matters suffices, along with other and 



equally distinctive points of structure, to separate the higher plants 



(or Phanerogams] from the lower or flowerless plants ( Cryptogams). 



But, selecting the flowering and higher plants themselves, we may 



readily discover that certain highly distinct 



types are represented within their limits. 



Thus, when we watch the development of an 



oak, a bean (Fig. 15), a primrose, or a buttercup, 



for example, we discover that the young plant 



develops or possesses two primitive leaves, 



named " seed-leaves " the cotyledons (c) of 



the botanist (Fig. 15). Again, such plants.have 



their flower-parts arranged in fours or fives ; 



and, whilst their stems grow outwards, the 



leaves present us with the network of veins /, young stem , r,theyou'ng 



(Fig. 1 6) so well seen in "skeleton leaves." root> 



These characters suffice to group the highest plants 

 into a type known as that of the Dicotyledons. 



If now we examine a palm, a lily, a tulip 

 (Fig, 17), or a hyacinth, we shall find that only 

 one "cotyledon" or "seed-leaf" is developed 

 by the young plant. Furthermore, the leaves 

 have parallel veins a conformation well illus- 

 trated in the tulip leaf (Fig. 18) and the 

 onion leaf, for example. Again, the stem of 

 these plants is an " inward-growing " structure, 

 and the parts of the flowers are developed in 

 threes or in multiples of that number. Hence 

 a second type of plants is constituted by the 

 palms, grasses, lilies, and their allies, and to this 



type the name of Monocotyledons is applied. 



A third type of plants is also included in the group of " flowering 



plants. " This latter type is constituted by 



the conifers, or " cone-bearing " plants 



such as the larches, firs, cedars, cycads, 



araucarias, cypresses, junipers, &c. and 



presents in many respects clear evidence 



of its title to be regarded as a highly dis- 

 tinctive and specialised group of plants. 



The chief characters of these plants con- 

 sist in the peculiarity of their flowering 



arrangements, which are represented in 



the well-known "cones." Again, the 



seeds are not contained within a seed- 

 vessel, as in ordinary plants (e.g. pea), but are borne on the cones. 



FIG. 16. LEAF OF DEAD- 

 NETTLE. 



FIG. 17. TULIP IN SECTION. 



