430 INTRODUCTION TO CRYPTOGAMIC BOTANY. 



tion of siiperficial bristles, and of descending threads like those 

 of some Callithamnia (Fig. 26), vary, but the deposit of mine- 

 ral matter in the cuticle, the coating of the axis, the form and 

 size of the nucules, are almost equally uncertain. The geo- 

 graphical limits of individual species are, therefore, frequently 

 doubtful, and will probably remain so till the effect of climate 

 and the chemical constitution of the water are known. Though 

 salt is injurious to most of the species, a few can bear brackish 

 water without injury. 



ALLIANCE IV. 



MuscALES, Lindl* 



Cellulares F0LIACE.E, D. C. — HETERONEMEiE, BurtL — MUSCOIDE^, 

 Li7idl. — Anophyta, B7idL — Muscos^, Perleb. 



Spores numerous (never at least solitary), produced within 

 variously formed capsulaeform organs, giving rise after germi- 

 nation to an annual or perennial frond, or foliiferous plant ; 

 Archegonia springing from the perfect plant, and producing 

 after impregnation sporiferous fruit, which is either sunk in 

 the frond, or superficial, with or without external envelopes in 

 addition to the calyj)tra or persistent Archegonium. 



475. Different as the horizontal Licheniform frond of many 

 Hepaticce is from the erect foliiferous mosses, a minute inspec- 

 tion of characters at once shows their intimate relation, and a 

 distinct connecting link presents itself in the genus Andrwa, 

 which, though essentially a moss, has something of the outward 

 habit and peculiar dehiscence of Jungerrtiannim. All agree 

 in producing from the germinating spores without any inter- 

 mediate prothallus, though there is something occasionally 



* Dr. Lindley includes Equiseta amongst Muscales. In other respects 

 Lis division is the same as mine. 



