SECRETARY'S RErORT. 73 



In grasses we meet with the following parts, all of which though 

 tolerably constant in form in individuals of each species, yet in their 

 variations in different species make up the sum of those distinctive 

 characters which enable the botanist to separate one species from 

 another. Such are 



The Root^ or descending axis, consisting of root fibres and rhi- 

 zome ; 



Culm^ or ascending axis, consisting of stem with its nodes and 

 joints ; 



Leaves^ the appendages of the axis, consisting of sheath, ligule 

 and lamina ; 



Floivers^ or reproductive oro^ans, consisting of floral envelopes, 

 stamens and pistils ; 



Seeds, or fruit, consisting of grains of various forms and sizes. 



The roots of grasses usually consist of small fibres, which in start- 

 ing from the seed, burst through the radicle or seed-root like the 

 inner valve of a telescope from the outer ; this, which is called by 

 the botanists, endorhizal, from two Greek words signifying, loithin 

 a sheath, may well be observed in the germination of such large 

 grasses as are presented in the cereals, as corn, wheat, barley, &c. 

 Eoots are sometimes hard and wiry, especially in such species as 

 grow in damp and boggy places ; whilst in others they are exceed- 

 ingly flexile, the main roots often creeping great distances in search 

 of food, and then branching off into innumerable fibrils or rootlets, 

 the ends of which, consisting of the newest cells or growth, form the 

 spongioles or suckers by which nutriment is taken from the soil into 

 the plant-system. It is hence necessary in the cultivation of grasses 

 that the soil for the reception of the seed should be of good tilth, 

 and especially that its mechanical consistency should be such that 

 it will not greatly expand in moisture and so push the roots out of 

 place, or crack in drought, in which case the rootlets or active parts 

 in life and increase are broken away just at the period when they 

 are most required. Roots are without buds, from which it will be 

 seen that all the parts of a grass which grow beneath the surf;ice are 

 not always true roots, such for instance as the runners in the com- 

 mon couch or witch grass, (^Tritiami repe7is.) These receive the 

 name of Rhizomes, or underground stems, and it is by means of 

 these that the couch tribe of grasses so quickly spread from a com- 



