"X 



36 REVUE BRYOLOGIQUE 



Fig. 3. One of the upper leaves, showing cluster of* stalked' 



gemmae borne on the nerve (X 35). 

 » 4. The same, with gemmae fallen off (X 25). 

 » 5. Apex of gemmiferous leaf (X 100). 

 » 6. Multicellular gemma (X I'^O). 

 » 7. " Normal" leaf (X 25). 

 » 8. Apex of same (X 170). 

 » 9, 10, 11. Transverse sections of a leaf at the base, 



middle, and towards the apex (X 270). 

 » 12. Areolation at base of leaf (X 270). 

 » 13. Ditto at two-thirds the length of the leaf (X 270). 

 )) 14-19. Copies of Schimper's original drawings, in the 



Kew Herbarium (reduced one third). 



^ 



A Rem.arkable Form of Trichostomum tortuosum 



.t 



A short time ago Prof. Barker sent me an unnamed moss 

 which he had gathered in July, 1870, on a rock in the 



neighbourhood of King's House, Glencoe, in the Western 



Highlands of Scotland. The plant was barren^ and formed 

 a dense tuft about an inch (2-3 cm.) high, pale yellowish 

 green on the surface and of a brownish yellow within, 

 with copious brown tomentum at the base. The leaves 

 were densely crow^ded, narrow^ ligulate, 4-6mm. in length, 

 and broadly obtuse and rounded at the summit, sometimes 

 even slightly widened so as to become spathulate, and 

 often markedly concave and cucullate. When dry they 

 became incurved and curled, shining at back, and undu- 

 late at the margin. The very wide, stout nerve (averaging 

 one-third the width of the leaf at base) tapered away 

 gradually above, and disappeared entirely at some distance 

 below the apex. The form of the leaf ^*7as in short almost 

 precisely that of Scopelophiia ligulata Spr. {Mercejja 

 Schpr.), differing only in the slightly narrower, more 

 ligulate outline. The areolation ot that species however 

 sufficiently distinguished it from the Scotch plant, for 

 while the upper cells were not dissimilar, the lower areo; 

 lation of the latter was very different. It agreed in fact 

 precisely with the characteristic areolation of that group 

 of species of Trichostomum (ftavO'Virenb, tortuosum^ etc.) 

 which have the hyaline basal cells clearly marked off from 

 the upper ones and extending obliquely upwards from the 

 nerve so as to reach much higher at the margin than at 

 the middle of the leaf. 



After much hesitation I have been driven to the conclu- 

 sion that the plant is after all but a remarkable form of 

 T. tortuosum^ in spite of the notable difference in the apex 

 of the leaf. In all other respects the characters of the plant 



