BRYOPSIS. 



[ 101 ] 



BRYUM. 



longitudinal line in the middle, lamellate 

 within, hygroscopic. Intenial : a large 

 delicate membrane with sixteen keels, jDro- 

 duced into more or less perfect lanceolate 

 teeth, often with intermediate cilia, some- 

 times without. Capsules mostly annulate. 



BiBL. See MuscACE^. 



BRYOPSIS, Lamouroux. — A marine 

 genus of Siphoneae (Confervoid Algse), of 

 which the British species form beautiful 

 green, somewhat elastic, feathered silky tufts, 

 from r'to 4" high upon rocks or upon other 

 Algae, in tide-pools. The whole axis and 

 proper branches of each plant consist of one 

 large ramified cell, the cavity being continu- 

 ous throughout, the membranous wall rather 

 thick, somewhat gelatinous externally ; the 

 branches are naked below, but clothed above 

 by small ramuli, arranged like leaves, disti- 

 chously, spirally or irregularly. The main 

 axes and branches grow indefinitely by de- 

 velopment of the apices, the ramuli are 

 limited in their development, and they are 

 ultimately shut off by septa, at last falling 

 off by the circular rupture of their wall, just 

 above theu' point of origin. 



When examined early, the ramuli are 

 found to have their walls lined with largish 

 elliptical green grains, each of which has at 

 first a round lia-ht central bodv, colourable 

 blue by iodine when fully formed (starch- 

 corpuscle). The branches exhibit the phae- 

 nomenon of reproduction, in irregular order, 

 in the following way. The green bodies on 

 then* walls multiply by subdivision, and 

 mcrease in size and number until they com- 

 pletely fill the tubular cavity of the ramule, 

 pressing upon one another so as to form a 

 compound dark green mass. A peculiar 

 swarming movement is next observed in the 

 green bodies, which increases more and more, 

 and the parent tube opening by a pore near 

 its apex, the green bodies escape, as elongated, 

 pear-shaped zoospores or active gonidia, 

 with cilia, according to Thuret two and four 

 in B. hypnoides, only two in B.plumosa. The 

 successive emission of the gonidia from the 

 various tubes of one plant occupies several 

 days. 



After the gonidia have come to rest, they 

 acquire a spherical form and gradually 

 increase in size ; at the end of a month or 

 six weeks their diameter is twice or thrice 

 the original dimensions, and then they begin 

 to elongate into a tube similar to the parent. 

 Agardh found them elongate, either in one 

 direction or in two, at first, but one end soon 

 swelled into a thickened organ of attachment. 



while the other began about the sixth week 

 to branch. British species : — 



1. B. plumosa, Huds. Deep green, I to 4 

 inches high, more or less branched : the 

 branches pinnated with sub-opposite disti- 

 chous or rarely irregular ramules. Harvey, 

 Br. Marine Alffce, 2nd ed. pi. 24 B. ; Phycol. 

 Brit. pi. 3 ; Greville, Algce, pi. 19 ; Engl. 

 Botany ( Ulva plumosa), 2375. 



2. B. hypnoides, Lamour. Yellow-green, 

 2" to 4" high, more slender and more 

 branched, branches repeatedly divided, ra- 

 mules irregularly scattered, somewhat pin- 

 nate, more or less dense. Harvey, Phyc. 

 Brit. pi. 119. 



BiBL. Systematic, as above, and Klitzing, 

 Sp. Alg. p. 490; Physiology, &c., Agardh, 

 Ann. des Sc. nat. 2 ser. vi. 200. pi. 12; Na- 

 ge\i, Zeitschr. fur Wiss. Bot. 1844-6 (transl. 

 in Ray Society's Volume, 1845, p. 269. pi. vi. 

 figs. 11-12, 1849, p. 97. pi. 2. figs. 1-3); 

 Neuern Algen-Systeme, Zurich, 1847, p. 171. 

 pi. 1. figs. 44-56; Thm'et, Ann. des Sc. nat. 

 3 ser. xiv. 8. pi. 16. figs. 1-6 ; Alex. Braim, 

 Verjungung, 137, &c. {Rejuvenescence, &c., 

 Ray Volume, 1853, p. 129, &c.). 



BRYUM, Dill. — A genus of operculate 

 Mosses, usually acrocarpous, containing a 

 large number of British species, even in its 

 restricted condition. 



1. Bryum roseuni, Schreb. 



2. Br. pallens, Sw. := B. turbinatum. 

 Hook. ex. part. 



3. Br. pseudo-triquetrum, Hedw. = B. 

 ventricosum, Dicks. 



4. Br. turbinatum, Hedw.=:JB. nigricans, 

 Dicks. 



5. Br. lacustre, Blandov.=-B. ccespititium, 

 var. Hook, and Tayl. 



6. Br. inclinatum, Br. and Sch.^B. ven- 

 tricosum, var. Hook. 



7. Br. uliginosum, Br. and Sch. 



8. Br. torquescens, Br. and Sch. 



9. Br. intermedium, Brid.=:B. turbinatum, 

 var. Hook. 



10. Br. capiUare, Hedw. 



11. Br. obconicum, Hsch. 



12. Br. ccespititium, L. 



13. Br. alpinum, L. 



14. Br. cyclophyllum, Br. and Sch. = B. 

 obtusifolium. Turn. M. Hib. 



15. Br. Zierii, Dicks. 



16. Br. demissum. Hook. 



17. Br. carneum, L. 



18. Br. albicans, Wahlenb. 



19. Br. Tozeri, Grev. 



20. Br. argent eum, L. 



21. Br. julaceum, Sm. 



