f)St 



solutoly ufcosiiai) to llio growth o( land-plants, ami that the gioon i-uUmi' of tlu'iv I'o- 

 liaj>v altogotlun* ilopomls upon its supply : anil if they bo plaooil ia evtni partial dark- 

 ness, the given uniekly acquires a siekly yellowish hue, aiul finally heeonies whitish. 

 Unt with Algw it is ditVerent. At enornunis depths, to whieh the linninous rays, it is 

 known, do nt»t penetrate, species exist as fully coloured as those along tlu" shore. They 

 tlioix'fiux', in this respect, either ditVer from all other plants (l''iiugi iucUided), or per- 

 haps, what arc called the chtiniral niys, in which seem to reside the most active prin- 

 ciples of solar light, may be those which cause colour among vegetables, and these mat/ 

 penotKVto to depths to which luniiuous rays do not reaoh. But tliis is move supposi- 

 tion, liainouroux suggests that ' the particles of light, or its elementary molecules, 

 oonibiued or niixcil with the water,' sufhcc for this purpose. lli)wever this may be, it 

 is wi>vth remarking that this property among Alga>, of producing vigorous growth ami 

 strong ci>lour without the agency of light, atVortls aiuithcr link between them and the 

 animal kingdom, among the lower tribes of which, light is by no means essential to 

 givwtli and the most brilliiuit colour." — p. ix. This passage is iuterestiug' in itself, 

 and in some nicasuiv applies to the subject of tJie preceding communication. — Ed.'] 



289. Kott' OH Viri parous Grasses. It appears to nio that some 

 misappvehonsion exists with veganl to Avhat are called " viviparoivs" 

 grasses. 1 have several times been deceived by the term, and should 

 like to see the matter cleared up in the pages of 'The Phytologist.' 

 Ill works of authority we are told that "in wet seasons tlie seeds of 

 grasses freipiently germinate before they fall from the husks, and that 

 a crop of young plants at the sumniit of the pai-eut stem is the conse- 

 quence," or words to that effect. Now in the greater part, or all the 

 cases of viviparous grasses which have come lutder my observation, 

 the plants hare never Jiowered at all, tmd of course produced no seed. 

 Wow far, ('// passd/if, may this circumstance be considered as illus- 

 trating the morphological doctrine, that every llower is but a stunted 

 branch ? Festuca ovina, ^. inripara, growing in my garden, produces 

 heads of young plants in the above manner every year, but never Uow- 

 ers at all. That such is the case with wild specimens of this and 

 other species that are found viviparous, we are by no means led to 

 suppose; in fact we are informed just the opposite. Do the seeds of 

 pastm-e grasses ever germinate in the husk, like wheat, when it is said 

 to " sprit " ? The following ai"e the grasses which I possess or have 

 heard of as being occasionally viviparous. — Nardus stricta, Alopecu- 

 rus pratensis, Agrostis vulgaris and alba, Aira c;vspitosa and alpina, 

 Glyceria lluitans, Poa alpina, Dactylis glomerata, Cynosunrs cristatus, 

 Festuca ovina and duriuscula, and ? Lolium perenne. — Leo. H. Grin- 

 don ; S'2, Higher Temple Si., Manchester, March 13, 1843. 



290. Note on Polygonum Convolvulus. We have a beautiful vari- 

 ety of Polygonum Convolvulus growing in many places about Man- 

 chester, with winged fruit, and so exceedhigly luxuriant in growtli 



