192 OF THE PERICHiETIUM. 



6. Perichcetwm, f. loO. A scaly Sheath, investing 

 the fertile flower, and consequently the base of the 

 fruit-stalk, in some Mosses. In the genus Hypnum 

 it is of great consequence, not only by its presence, 

 constituting a part of the generic character, but by 

 its differences in shape, proportion, and structure, 

 serving frequently to discriminate species. SeeEfigL 

 Bot. t, 1037—9, 1182, 1445—8, &c.; see also 

 the same part in Neckera, t. 1443, 4. Linnaeus 

 appears by his manuscripts to have intended adding 

 this to the different kinds of calyx, though it is not" 

 one of the seven enumerated in his printed works. 

 Nor is he, surely, correct in allowing it to the 

 genus Jimgermamiia, The membranous part which 

 he there calls perichcetium is strictly analogous in- 

 deed to the calyptra^ f. 1.51, 152 b, or veil of real 

 mosses, esteemed by him a kind of calyx ; but as I 

 presume with Schreber, to reckon it rather a corolla, 

 and Hedwig once thought the same, and as Jiinger- 

 mannici has more or less of a real calyx besides, 

 f. 152 a, see E7igl. Bot. t. 77\, &c., I would no 

 longer apply the term perichcetium to this genus at 

 all. 



The part called calyptra being removed from the 

 list, as being a corolla, the perichcEtium takes its 

 place among the seven kinds of calyx. We lay less 

 stress upon this coincidence than Linnseus might 

 have done, when, according to the fashion of the 

 times, he condescended to distribute his immortal 



