8PECIES OF MOSSES OF THE GENFS FISSIDENS. 551 



it will be found that it is the fruiting stems which are annual, 

 and that they arise from the axils of the leaves of the stems of 

 the previous season ; and if the older stem has sufficiently de- 

 cayed, these annual shoots, bearing male and female flowers both 

 from the same axil and rooting at their base, appear at the fruiting 

 season as independent stems j if the older stem does not decay, 

 such forms as that observable in IP. inconstant are produced. 



Most of the small apical fruiting species produce their fruit 

 without any special leaflets, usual in other mosses, surrounding 

 the female flower ; these are, however, present in the lateral 

 fruiting species. There is also great diversity in the male inflo- 

 rescence ; it may be, like the female, apical, or it may in the same 

 species appear basal, from the short stem on which it is borne ; 

 it may be bud-like, in the leaf-axils of the fruiting-stem ; and it 

 may also be a bunch of naked antheridia, or even a single anthe- 

 ridium naked in the leaf-axils, — all which states may occur on 

 the same stem. The small calyptra in the lesser species may be 

 found carried up on the operculum entire, or in the same species 

 it may be split on one side. 



Dillenius first defined more nearly the species, which became 

 afterwards named Rypnum adiantoides, R. taxifolius, and H. 

 bryoides by Linnaeus. 



Hedwig, investigating the inflorescence, figures that of Rypnum 

 bryoides, Theor. Gen. et Fruct. PL Crypt, p. 148, t. xi. ; here 

 it is still Rypnum. Later he figured on a grand scale Fissidens 

 bryoides, Muse. Frond, iii. xxix.,— two fertile stems complete, at 

 their side a stem almost attached by roots, having at its apex a 

 male flower, apart from these a stem with axillary male flowers 

 only, as in his previous figure. The often-excluded fig. 10, when 

 this plate is referred to, is correctly the enlarged apical flower 

 belonging to the principal figures. Here then, quite uncon- 

 sciously to himself, he had figured a species distinct from that of 

 bis first work ; or it may be said the idea of it had become dual. 

 The overlooking and mistaking of the import of this figure has 

 made much confusion. Dickson sent to Hedwig a specimen of 

 his Bryum viridulum, which, he says, was the same as he had 

 found in the herbarium of Linuams. To this Hedwig gave the 

 name Fissidens exilis, because it was so small ; and it is figured 

 in a very inferior manner in bis posthumous work continued by 

 Schwaegrichen, t. 38, where it has entire leaves. Swam de- 

 scribed his Dicranum viridulum, Weber and Mohr J), mcurvum, 



