LiMPETCHT : Systematic Arrangement of Bog Mosses. 143 



poroseless cells, round a sometimes reddish wood cylinder. About 

 this fact Warnstorf, I.e., p. 72, has the following — " That the mar- 

 ginal cells are proportionally somewhat larger, I find accounted for 

 through the station being in or about water." 



Unfortunately the typical S. spectabile grows deep in the water of 

 sylvan streams, mostly with their heads only emerging ; S. fallax is 

 also as deeply submerged in turfy districts, and in both the stem- 

 bark is wanting. So far as I can tell, there are no examples amongst 

 our Sphagna which afford any grounds for such an assertion. 



Whilst with some bog mosses numerous varieties and forms are 

 shewn (Warnstorf describes those of S. acutifolium alone as 23 !) we 

 seek in vain in the literature of other spe<iies — viz., with 6^. Lind- 

 he^-gii, Ang8trowi% molle, &c. — for such ; so that the idea gains ground 

 that these rare Sphagna have no tendency to vary. 



I took occasion, upon my last excursion in the Reisengebirge, to pay 

 particular attention to this peculiarity with regard to S. LmdbergiL 

 Since this species possesses a great power in adapting itself to its 

 conditions (Milde found it, as is well known, upon Moorland near 

 Nimkau, in the Silesian plains), so it has also its corresponding 

 circle of forms which represent in its links the varieties of the allied 

 species, so that one can hold as distinct also for *S'. Lindbfrgii, forms 

 such as tenellum^ compactum, sqn.arrosulum, and immersum. 



There are often found forms in one and the same locality of the 

 Weissen Wiese, in the Riesengebirge, according as the moss comes 

 from the dry moor or gradually grows deeper in the swamps until 

 entirely swimming, and in company with S. cuspidatum, which are 

 only to be distinguished from it by the stem-leaves, since the bark 

 and wood entirely lose their characteristic colour. 



What, finally, the grouping of the European bog mosses will arrive 

 at, if based upon one single character — be it according to the stems 

 bark, or be it according to the disposition of the chlorophyllose cells 

 in the branch leaf, or according to the form of the stem-leaves, — if 

 each division be rigorously carried out, it will clearly be an artificial 

 system which will separate far asunder nearly-allied species and 

 forms : therefore I recommend, as more perfect and satisfactory, a 

 grouping of the species according to their natural relationship, as was 

 first accomplished by Lindberg, then by Schliephacke, Russow, and 

 others. 



