HEMIONITIS. 



[ 318 ] 



HEPATICACEJE. 



H. antarcticus (PL 19. fig. 3). 



The species (two) appear to consist of 

 EiddulphicB, with the ends of two of the pro- 

 cesses broken off. Ehrenberg remarks that 

 in one specimen he could not detect the 

 apertures, perhaps on account of the position 

 not being suitable ! 



BIBL. Ehrenberg, Eer. d. Berl. Akad. 

 1844, p. 199. 



HEMIONITIS, Linn. A genus of Gym- 

 nogrammese (Polypodaeous Ferns) with a 

 very elegant reticulated arrangement of the 

 sori. 



HEMIPTERA. An order of INSECTS. 



HEMIPTYCHUS, Ehr. See ARACH- 



NOIDISCUS. 



HEMITELIA, Presl. A genus of Cya- 

 thaeous ferns. Exotic. 



HEMIZOSTER, Ehr. A genus of sili- 

 ceous fragments of some unknown substance 

 or body ! 



BIBL. Ehrenberg, Eer. d. Eerl. Akad. 

 1844. p. 199. 



HEMP. The ordinary name of the fibre 

 of Cannabis sativa, consisting of the liber- 

 fibres of this plant (PI. 21. fig. 6). It is ap- 

 plied to some other substances used for the 

 same purposes, e. g. Manilla-hemp (the fibre 

 of MUSA) &c. See TEXTILE FIBRES and 

 LIBER. 



HENDERSONIA, Berkeley (Sporoca- 

 dus, Corda, in part). A genus of Sphaero- 

 nemei (Coniomycetous Fungi), interesting 

 as having furnished one of the earliest dis- 

 covered examples of two forms of fructifica- 

 tion, leading to the abolition of the distinc- 

 tion between Coniomycetous and Ascomyce- 

 tous Fungi (CONIOMYCETES). Mr. Berke- 

 ley has seen two conditions of spores in H. 

 mutabilis, and he states that Fries informs 

 him of the observation of asci and septate 

 naked spores conjointly in Hendersonia Sy- 



Fig. 320. 



Hendersonia. 



Spores on the perithecium. 

 Magnified 200 diams. 



ringa. Several British species have been 



described. They form dark spots or patches 

 on the stems of herbs or twigs of trees ; the 

 dark matrix having a perithecium excavated 

 in it, lined by a gelatinous stratum, on which 

 stand stalked fusiform septate spores (fig, 

 320). 



1. H. elegans, Berk. (Ann. Nat. Hist. vi. 

 pi. xi. fig. 9). On the culms of reeds. 



2. H. macrospora, Berk, and Broome (I. c. 

 2nd ser. v. p. 3/3). On dead twigs of Phi- 

 ladelphus. 



3. H. arcus, Berk, and Br. (I. c.). On Box 

 twigs. 



4. H. mutabilis, Berk, and Br. (I. c.). On 

 dead twigs of Plane. 



5. H. polycystis, Berk, and Br. (/. c.). On 

 dead twigs of Birch. 



6. H. macropus, Berk, and Br. (I. c.). On 

 dead leaves of Carex. 



7. H. typhoidearum, Desm. (Desmazieres, 

 Ann. des Sc. nat. 3rd ser. xi. 344). On dead 

 leaves of Typha, &c. 



8. H. Stephensii, Berk, and Br. (Ann. Nat. 

 Hist. 2 ser. viii. p. 95). On dead stems of 

 Pteris aquilina. 



9. H. fibriseta, Berk. (Hooker's Journal 

 of Botany, iv. p. 43). On Birch planks. 



BIBL. Berkeley and Berk, and Broome, 

 Annals Nat. Hist. 1. c. ; Hooker's Journal 

 of Botany, iii. 319; Fries, Summa Veget. 416. 



HEPATICACE^E. An order of the 

 Muscales (Cryptogamous Plants), consisting 

 of plants of "small size, varying much in 

 structure, inhabiting damp spots on the 

 ground, rocks, or trees, or floating on water. 



The vegetative structure of the lowest 

 forms consists simply of a patch of green 

 membrane, spreading over the ground, com- 

 posed of a single (Anthoceros leevis) or dou- 

 ble (Sphcerocarpus terrestris) layer of cells 

 containing chlorophyll. In Marchantia 

 (see MARCHANTIA) there is an advance; 



Fig. 321. 



Fig. 322. 



Fimbriaria fragrans. 



Fig. 321. Lobe of a frond. Nat. size. 

 Fig. 322. Section of frond, showing two immersed 

 antheridia. Magnified 40 diams. 



the frond not only exhibits more definitely 

 characterized lobes, but also a considerable 



