GRAMINACE^ 



185 



compound microscope, or, more frequently, the testa is com- 

 pletely destroyed before the fruit is ripe. This fruit is distin- 

 guished under the name of caryopsis. A grain of wheat 

 (fig. 28), or a so-called grass-seed, is in reality a fruit, because 

 the ovary takes part in its formation. Often, the palese persist 

 and continue to envelop the ripe fruit. Usually the fruit is 

 grooved along one side (ventral side). Seed. — This has 

 already been described (page 19); it is endospermic, with an 

 embryo of peculiar structure. 



