OF THE GRAMINEJE. 593 



observed), serves a purpose much more important 

 in the economy of these plants, than producing 

 the radicles, or " les racines articulaires," as M. 

 Mirbel terms them. The seminal Tuber is indeed 

 analogous with those of the stem, both being the 

 organs in which the bulbs of these plants are form- 

 ed and matured ; but the *f racines articulaires" 

 of M. Mirbel are in reality young plants, (PL XIII. 

 figs. i. and 3.), the roots of the Gramineae being 

 invariably fibrous. Offsets from the seminal tuber 

 indeed sometimes put on the appearance of roots ; 

 but a closer examination, as they advance in size, 

 proves them to be the stems of young plants*. 

 It is singular that M. Poiteau, in a memoir in 

 other respects highly valuable, published in the 

 same Journal, (cahiers 3. and 4.), should have 

 mistaken the rudiment of the second seminal 

 bulb (PL XIII. fig. 2.) for another cotyledon, and 

 from this circumstance inferred, that the Grami- 

 neae were nearly related to dicotyledonous plants : 

 " Si les gramin£es se rapprochent les cyperacees par 



* p 



* It is in a great measure by means of these lateral 

 shoots, and their tubera, that bushes, consisting of from 

 sixty to several hundred stems, originate from one seed. 

 The production of these offsets is frequently accidental : 

 If the seed be buried under a stone, or an indurated lump 

 of clay, the seminal bulbs cannot shoot to the surface, 

 but stems are sent off, in a horizontal direction, as in Tri- 

 txcum repens, until they effect their escape upwards. 



