192 OF THE PERICHYETIUM. 



6. Perichcetium, f. 150. 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. See.E//g7. 

 Sot. t. 10379, 1182, 14458, &c.; see also 

 the same part in Neckcra, 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 Jungermannia. The membranous part which 

 he there calls perich&tium is strictly analogous in- 

 deed to the calyptra, f. 151, 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 Hedv/ig once thought the same, and as Junger- 

 mannia has more or less of a real calyx besides, 

 /. 152 a, see Engl Sot. t. 771, &c., I would no 

 longer apply the term perictuztium to this genus at 

 all. 



The part called calyptra being removed from the 

 list, as being a corolla, the per idlest ium takes its 

 place among the seven kinds of calyx. We lay less 

 stress upon this coincidence than Linnaeus might 

 have done, when, according to the fashion of the 

 times, he condescended to distribute his immortal 



