84 BOTANY 



feed his sheep or cattle. Nearly all have highly differ- 

 entiated organs, with wood and vessels more differ- 

 entiated than in the other groups. The majority of 

 them have zones of secondary thickening, and all have 

 the reproductive organs on special leaves, generally 

 arranged together in " flowers," most of which are 

 brightly coloured and ornamental. To many collectors 

 tins group alone constitutes the " flora " of a district, 

 and the number of families it comprises is in proportion 

 to the huge number of species it includes. When this 

 group is further examined, there are found to be two 

 well-marked divisions of it called the Monocotyledons 

 and the Dicotyledons. The first has embryos with only 

 one cotyledon or " seed leaf," the second has embryoa 

 with two. In the first group the leaves are generally 

 long and narrow and have parallel veins, while the 

 stems do not have secondary wood ; in the second 

 group the veins are reticulate, and the ring of primary 

 bundles augmented by secondary thickening. To the 

 former belong the Grasses, Palms, Lilies, and Orchids, 

 and to the latter all the leafy trees like the Oak, Beech, 

 and Maple, the majority of crops such as the Cabbage, 

 Peas, and Strawberries, and flow r ers such as the Rose, 

 Daisy, and Clematis. The families in both the two 

 groups are separated principally according to the numbers 

 of the parts in the flowers, and the relative positions 

 of these parts which, on the whole, seem to bring to- 

 gether the species which are truly like each other. 

 Speaking generally, one may say that there is a pre- 

 ponderance of four or five, or multiples of these numbers, 

 in the flower parts of the Dicotyledons, with an almost 

 universal appearance of three or its multiples in the 

 flower of the Monocotyledons. The details of the 

 classification of the families will be found in any flora, 



