340 THE JOURNAL OF BOTANY 



On sending a copy of my paper to Dr. Hagen, he at once wrote 

 to me that the leaf-stracture of Oligotrichum, Lescurii, as shown in 

 my figure, exhibited tlie generic characters of Pliilocnja, and sug- 

 gested that 0. Lescurii ought to be transferred to Philocrya. Dr. 

 Hagen kindly sent me a small fragment of Philocrija aspera (now in 

 the Kew Herbarium), so that I have been able to compare the 

 structure of the leaves in the two plants. In P. aspera we find 

 that, as stated by Hagen and Jensen, the lamellae are confined to 

 the nerve, and that, proceeding towards the margin, we come to a 

 bistratose lamina, with projecting cells on the ventral surface; then, 

 usually, there are a few rows unistratose, ending in a single bi- 

 stratose row of marginal cells. This is essentially the same structure 

 as is found in 0. Lescurii (see Journ. Linn. Soc. I.e. f. 20), although 

 in Pkilocnja aspera the following minor differences are to be noted : 

 the nerve is more widened and flattened, plane and not convex on 

 the ventral surface, and bears a greater number of lamellae (about 

 thirty-two) ; the ventral cells of the bistratose part of the lamina 

 (especially towards the nerve) are slightly larger in proportion to 

 the size of the dorsal cells, and project more. (These projecting 

 cells are perhaps to be considered as rudimentary lamellae, like the 

 projecting cells occasionally present on the nerve in Polytrichitin 

 gijmnophyllum Mitt. {I.e. p. 461, f. 19). In this connection it is 

 interesting to note that Hagen and Jensen figure one of these pro- 

 jecting cells in Philocrya aspera growing out and becoming divided 

 off to form another cell, so that the leaf there bears, practically, a 

 low lamella.) 



The true affinity of Philocrya, however, I have been able to dis- 

 cover by a fortunate coincidence. In examining a few mosses lately 

 brought back from China by Dr. A. Henry, I found amongst them 

 a Polytrichoid moss with one old capsule. From the examination 

 of this capsule I found that the moss belonged to Lyellia, and a 

 comparison with Indian specimens of Lyellia crispa R. Br. showed 

 that the Chinese plant was that species. A detailed examination 

 of the leaf of L. crispa, however, showed exactly the same structure 

 as that of Philocrya, as can be seen by referring to fig. 14 on 

 Plate 426, which shows part of a transverse section of a leaf from 

 Dr. Henry's Chinese example of Lyellia crispa. The specimen of 

 ''Philocrya aspera'' sent to me by Dr. Hagen consists of only a 

 small fragment, and in the absence of fuller material it is difficult 

 to decide whether ''Philocrya aspera'' has been founded on merely 

 barren Lyellia crispa, or whether the Greenland moss forms a new 

 species of the genus. I am inclined to the former view, as in the 

 shape and areolation of the leaf, and in the position and structure 

 of the lamellae, no difference can be found in the two plants. 

 However this may prove to be, it is clear that the genus Philocrya 

 must be sunk in Lyellia. 



The " minute pores" described by Robert Brown (Trans. Linn. 

 Soc. xii. p. 564) at the base of the capsule of Lyellia crispa, and 

 conjectured by him to assist in the dissemination of the spores, are 

 in reality very large stomata (with the guard-cells measuring as 

 much as 100 fx in length). These stomata agree in shape and 



