ORDER CYPERACE.E, OR 'SEDGE TRIBE. 555 



matter through which it is diffused ; hence this is consumed in 

 large quantities by perfumers and the makers of hair-powder. 

 It is also employed in medicine as a tonic and cordial. This 

 order is very interesting to the Physiologist, on account of the 

 example which it affords of the development of heat during the 

 process of flowering ( 419). 



732. There now only remain to be considered two orders of 

 Endogens, which bear a strong general resemblance to each 

 other, and, indeed, are not always readily separated. One of 

 these is that which has been spoken of as pre-eminently useful 

 to Man, the order GRAMINE^E, or Grass tribe ; the other, the 

 CYPERACE^!, or Sedge tribe, is almost as completely useless. 

 They agree in the peculiar character -of the floral envelopes, 

 which constitute what is known as the husk or chaff of corn, 

 the separate pieces or scales being termed glumes. These are 

 regarded by the scientific botanist as metamorphosed bracts. 

 The Sedges may be, for the most part, readily distinguished 

 from Grasses, by their having stems which are solid and angular, 

 instead of round and hollow ; besides which, there is no hard 

 partition at the joints. Moreover, the flowers are (with few 

 exceptions) only protected by a solitary glume or bract. In 

 some species all the flowers contain both sets of organs ; others 

 are monoecious, and others again are dioecious. The stamens are 

 usually three in number, but are sometimes fewer, and occa- 

 sionally more numerous. The ovarium is often surrounded by 

 little bristles, which are perhaps the rudiments of an unde- 

 veloped perianth, as no other traces of calyx or corolla can be 

 found ; it contains one seed ; and its style is usually single, 

 dividing at the top into two or three stigmata. The fruit, 

 when ripe, is a hard frequently three-cornered nut, indicating 

 tfie original formation of the ovarium from three carpels. The 

 seed presents a remarkable difference from that of Grasses ; for 

 the embryo is a minute roundish undivided body, lying buried 

 within the albumen, at its lower extremity, instead of being 

 placed on its side, as it will be presently shown to be in the 

 Grasses (. 735). 



oo 2 



