19: 



HARDWICKE'S SCIENCE-GOSSIT. 



[Sept. 1, 1868. 



makes some very curious motions, a short account 

 of which I will transcribe from my journal : — 



"The seed, with its inner or flowering glumes, of 

 this plaut is highly hygrometric, and when subjected 

 to moisture or, after being moistened, to warmth, 

 exhibits a series of interesting movements which 

 well repay the trouble cf examining them. 



Fig. 199. 



a. Panicle of Anthoxanthum odoratum. 



b. Inner glumes with awns containing ovary magnified, 



c. Inner glumes, ovary removed, magnified. 



d. Outer glumes— styles. 



"The flowering glumes are awned, the one from 

 the back, below the summit, by a straight and some- 

 what slender awn ; the other from the base by a 

 bent awn, larger and stronger. The glumes them- 

 selves are densely covered with stiff brown erect 

 hairs, particularly towards the base, where the hairs 

 are generally spreading somewhat after the style of 

 a cat's whiskers. The larger awn has much the 

 appearance presented by the posterior leg of a grass- 

 hopper. Indeed, the movements, general contour, 

 and colouring of the flower form a tout ensemble not 

 unlike that of an insect. Both awns, as seen under 

 the microscope or a good magnifier, are closely ser- 

 rated by stiff spines. I am at present engaged 

 making coloured illustrations of the grasses of my 

 own immediate neighbourhood, and while examining 

 the structure of the flower of this grass I was 

 much struck with its movements. I had laid the 

 flower, divested of its outer glumes, upon the palm 

 of my hand, which was somewhat moist with sweat, 

 and was examining it closely by means of a good lens, 

 when I first observed these movements. First the 

 bent awn began to screw itself round backwards 

 and forwards ; then the smaller awn did the same ; 

 then again the stronger awn alternately bent and 



straightened itself in a manner that seemed as deter- 

 minate and deliberate as though the result of vo- 

 lition. 



" The vessel, with its contained ovary, now rolled 

 from side to side, now over and over, and occasion- 

 ally made small leaps. I now placed it upon a piece 

 of blotting paper, and with the point of my pencil 

 let fall a drop of water upon the paper about four 

 lines from the flower. As soon as the water pene- 

 trated to the end of the awn, it jumped fully an 

 inch. This was repeated in the presence of three 

 or four gentlemen with the same result, much to 

 their amusement. 



" It is, however, impossible to describe fully the 

 sensitive powers of this flower. Every one may 

 witness them by procuring a few plants. 



" I found that on placing it upon damp earth it 

 frequently erected itself upon its base and partially 

 buried itself. Whether this is a provision for the 

 more certain germination of the seeds I can't say, 

 though it seems to me well calculated to produce 

 that result." 



The genus Hordeum (Barley) contains four British 

 species, all of which are easily recognized as be- 

 longing to the genus by any one who knows the 

 cultivated barley ; aud who does not? Even Miss 

 Kilmansegg, of whom it is said, 



She hated lanes and she hated fields, 

 She hated all that the country yields, 



And barely knew turnips from clover, — 



even she must have known the "golden barley." 

 They are by no means rare plants, two or three 

 species being within easy reach of almost all 

 English and Irish students. In Scotland the bar- 

 leys seem to be local or rare. They arc thus well 

 suited to furnish a lesson on grasses to the tyro in 

 tins branch. In this locality I have found three 

 out of the four species — viz., Wall barley (H. 

 miiriiium), meadow barley (Il.pratense), and sea- 

 side barley (//. maritimuni). 



The spikelets in all the species are situated three 

 together, either sessile or nearly so, in 

 alternate notches of the culm or flower- 

 stalk (fig. 200). In H. sylvaticum the 

 central spikelets are reduced to a pair 

 of barren glumes, while the lateral ones 

 are perfect. In the remaining three the 

 lateral ones are so reduced, while the 

 central one is perfect. 



Hordeum murinum (Wall Barley), fig. 

 201. — This is a rather stout grass, often 

 geniculate. The leaf sheaths are much 

 inllated. The panicle is longer and 

 stouter than that of II. pratense, II. 

 maritimuni, or //. sylvaticum. The awns 

 also are much longer. The central awns 

 are about three times the length of the inner glumes, 

 the exterior awn a little more than halt* the central 



Fig. 200. 

 Culm. 



