EQUISETACE^. 



243 ] 



ERVILIA. 



turn ; the end-cell grows on and multiplies in 

 both directions, until a tabulated prothallium 

 is produced; on this arise archegonia and 

 antheridia (on distinct individuals), resem- 

 bling in all essential respects those produced 

 on the corresponding structure in the FERNS. 

 After the fertilization of an archegonium, 

 the germ-cell contained in it becomes deve- 

 loped as an embryo, and a new Equisetum 

 stem of the ordinary structure springs up 

 (fig. 210), forming a creeping rhizome with 



Fig. 210. 



Equisetum arvense. 



Young stem arising from a prothallium. 

 Magnified 15 diameters. 



upright fistular shafts, resembling the parent 

 plant from which the spores were derived. 

 The family Equisetaceae is represented only 

 by a single genus in existing vegetation, 

 containing only herbaceous plants. The 

 Equisetaceae of former ages were far more 

 important as regards size. The follow- 

 ing may be given as the character of the 

 genus : 



Equisetum, Linn. Stems erect, cylin- 

 drical, smooth, striate, fistular, articulated, 

 simple or with whorled branches (occasion- 

 ally with whorled branchlets), bearing mem- 

 branous tooth-like leaves, connate and form- 

 ing a short erect sheath encircling each 

 articulation. Thecae unilocular, six or seven 

 together, adnate all round the under sur- 

 face of a peltate sporange; the sporanges 

 arranged in terminal spikes or cones. Spores 

 numerous, with four filaments arising at one 

 point, coiled elastically a few times round 

 the spore, and terminating in spathulate 

 ends, springing loose from the spore when 

 the latter is discharged. 



BIBL. Francis's British Ferns, 5th ed. 



1855 ; Thuret, Ann. des Sc. nat. 3 ser. xi. 

 p. 5; Milde, Bot. Zeit. viii. p. 448 (1850), 

 and x. p. 537 (1852), Linncea, xxiii. p. 545 

 (1850); Hofmeister, Vergleich. Unters. 1851, 

 Verh. k. Sachs. Akad. d. Wiss. iv. p. 123 ; 

 Bischoff, G. W., Kryptogam. Gewachse, 



1 heft. p. 27. pi. 3, 4, 5 (1838), Botan.Zeit. xi. 

 p. 97 (1853), transl. in Ann. des Sc. nat. 

 3 ser. xix. p. 232 ; Pringsheim, Bot. Zeit. 

 xi. p. 241 (1853). 



EREBONEMA, Rom. A supposed genus 

 of Kiitzing's family Leptomiteae. Some im- 

 perfect filamentous organism, probably be- 

 longing to a Fungus. 



BIBL. Romer, Deutschl. Ala. p. 70; Kiit- 

 zing, Sp. Alg. p. 157. 



ERETES, Wemeck. A genus of Infuso- 

 ria, of the family Cryptomonadina. 



Char. Those of Phacelomonas with a ca- 

 rapace. 



One species : the spores of an Alga (?). 



BIBL. Werneck, Eer. d. Berl. Akad. 1844. 

 p. 377- 



ERGOT and ERGOT^ETIA. See CLA- 



VICEPS. 



ERINEUM, Pers. A supposed genus of 

 Fungi, really consisting of abnormal deve- 

 lopments of the cells of the epidermis of the 

 trees upon which they are supposed to be 

 parasitic. They occur chiefly upon the Amen- 

 taceae, Aceraceae, and Rosaceae (Apple-trees, 

 Plum-trees, &c.). 



BIBL. Fries, Syst. My col. iii. p. 521 ; 

 Berkeley in Lindley's Veg. Kingdom, art. 

 Funaales. 



ERIOSPORA, Berk. & Br. A genus of 

 Melanconiei (Coniomycetous Fungi), de- 

 scribed (E. leucostoma] as forming minute 

 brown spots upon dead leaves of the bulrush. 

 The conceptacles are globose, and collected 

 in numbers on the stroma, bursting by a 

 single common (white-bordered) pore to dis- 

 charge the spores (stylospores), which are 

 filiform and very slender, and arise in fours 

 from a sporophore. Probably corresponds 

 to the genus Robergea among the Ascospo- 

 rous Fungi. (See CONIOMYCETES.) 



BIBL. Berk, and Br. Ann. Nat. Hist. 



2 ser. v. p. 455. pi. 11. fig. 1. 

 ERVILIA, Duj. A genus of Infusoria, of 



the family Ervilina. 



Char. Oval, compressed; carapace open 

 on one side and in front ; vibratile cilia issu- 

 ing from the fissure ; a lateral pedicle at the 

 posterior end of the body. Marine. 



E. legumen = Euplotes monostylus, E. 

 (PI. 23. fig. 52; b, side view). Body very 

 transparent, exhibiting vacuoles ; length 



R2 



