PHANEROGAMIA 521 



exocarp and a hard endocarp. Prunus Cerasus (Fig. 627), and 

 Juglans regia (Fig. 559), are familiar examples. 



Fruits which do not originate from the ovary alone are found in Rosa (Fig. 

 511), in which the succulent receptacle protects the partial fruits and still bears 

 the calyx on its margin, and in PhysaMs (Fig. 510), the berry of which is enclosed 

 in the greatly enlarged calyx. 



When on the other hand the group of fruits borne on an inflorescence has the 

 appearance of a single fruit the structure 

 may be termed a SPURIOUS FRUIT. The Fig 

 (Ficus) is the best-known example of this, 

 but similar spurious fruits are especially 

 frequent in the Urticaceae and Moraceae. 

 The comparison of a Blackberry which is 

 the product of a single flower with the 

 spurious fruit of the Mulberry will show 

 how closely the two structures may re- 

 semble one another (Fig. 512). 



The above enumeration of the most im- Fit;. 512. .4, Merocarpic fruit <>f Ruims fruti- 

 portant and frequently recurring forms of cosus '' consisting of a number of drupes ; 

 fruit is in no sense exhaustive. It should f ' inflorescenc of Mulberry (Moms nigra) 



bearing a number of small drupes. (After 



be added that the various forms are only DUCHARTRE ) 

 to be understood when regarded from an 



cecological point of view. The form and other peculiarities of the fruit must 

 be considered in relation to the distribution of the seeds. In the distribution of 

 fruits and seeds, as in the transfer of pollen to the stigma, different means of 

 transport, especially wind, water, and animals, are made use of by plants. (Cf. 

 the account in the physiological section, p. 318.) 



SUB-CLASS I 

 Monocotylae ( 13 ) 



The Monocotyledons, or Angiosperms which possess a single 

 cotyledon, are in general habit mostly herbaceous, less frequently 

 shrubs or trees. 



In germination the radicle and hypocotyl of the small embryo 

 emerge from the seed-coat, while the sheath-like cotyledon usually 

 remains with its upper end within the seed and absorbs the materials 

 stored in the endosperm, which is usually well developed. The 

 growth of the main root is sooner or later arrested and its place 

 taken by numerous adventitious roots springing from the stem. In 

 the Grasses these are already present in the embryo within the 

 seed. Thus a single root system derived by the branching of a 

 main root, such as the Gymnosperms and Dicotyledons possess, is 

 wanting throughout the Monocotyledons. 



The growing point of the stem remains for a longer or shorter 

 time enclosed by the sheath of the cotyledon. Later it bears in 



