The Scottish Naturalist. 171 



cortical cells to nourish the plant ; nor is an exact place in the vegetable 

 kingdom easily assigned to them, standing as they are supposed to do 

 between the Hcpaticcc and the true mosses, but generally included among 

 the latter. It seems to me that they might well form a distinct division 

 by themselves, as far separated as the Hcpaticcc from the true mosses. 

 Nor is their division into sections and species by any means easy. Under 

 these circumstances such a work as that now presented to us by Dr. 

 Braithwaite cannot but be welcomed by every one studying the faiflily. 

 The specimens are beautifully dried and pasted on white paper, and in 

 addition are loose specimens enclosed in a little envelope, for miscroscopic 

 use. The collection has been gathered from various places throughout the 

 British Islands, and in a few cases where the species is but sparingly found 

 in Britain, foreign specimens have been used to fill their place. The 

 whole have been collected by men well known as bryologists, and each 

 packet thoroughly examined by Dr. Braithwaite, who has made the 

 iSphagna his special study for many years. "We have thus before us a 

 work which may be relied upon as authoritative, and the value of the work 

 as a collection of British Sphagna will grow with its age. 



There are seventeen species shown in the work, and thirty-six 

 varieties, besides many forms exhibiting a character which is very ap- 

 parent in the Sphagna, that of eveiy good variety varying from the 

 tiniest form to the densest. I scarcely think it important to say much upon 

 what might be accounted a species or only ranked as a variety, as the term 

 species is simply a convenient one to indicate such forms as are more 

 definable than others, and in the present work there is almost no change in 

 that way but which has not been already adopted by Schimper in his Synopsis 

 of European Mosses. Still I cannot help feeling that S. riibelluin of 

 Wilson, being a dioicGUs species, has the same claim as *S'. sbictn7?i, which 

 arises from S. fimbriahan in the same way as 8. rubellum does from 

 ^S". acutifoliiim, although I am not sure but both might be better simply 

 set down as varieties. And S. papillosuju I must say I do not at all 

 understand and have never seen any reason for its being recognised as a 

 species. Nor is it necessary to refer very much to the nomenclature, 

 although the older names should in all cases be preferred, and certainly that 

 of S. rigidujH, Schimper, as adopted by Dr. Braithwaite, is no improvement 

 on co77ipactum Brid., which is the older, name; nor do I think 

 8. subsecundum any improvement on contortiwi. But I think the group- 

 ing of them into divisions is a more important matter, and scarcely meets 

 my view in this or any of the other works on Sphagna that I know. 



The system adopted in the present work is pretty much Dr. Braithwaite's 

 own, being nearly Schimper's system reversed, only in section D.-Cnspidata 

 of this work is included Schimper's three divisions — Acutifolia, Cuspidata, 

 and Squarrosa ; while the Mollia of Schimper's is Trimcata of Braithwaite. 

 But neither system is veiy much to my mind : still I would prefer that of the 

 present work to that of Schimper's Synopsis, Truncata being a better name 

 for a division, including S. molle, 8. Angstromi, and '6". ris^idu??i, than 

 Mollia, that being inconsistent with the character of r\gidtwi and even 

 Cttspidata, fully equal to the three terms used by Schimper. But I think 

 a more natural division than either would be to divide the whole Sphagna 

 into three classes, having reference to the stem leaves alone — the first 

 Fimbriata, having the stem leaf fimbriated ; and the second Acuta, having 



