ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 275 



As regards any system of classification derived from anatomical 

 characters, the separate families show in general a characteristic 

 structure, and this is sometimes also the case with individual genera ; but 

 a general classification of all ferns cannot be established in this way. The 

 author considers also that the examination of the leaf-stalk cannot be 

 employed for purposes of classification in palaeontology, since it is usually 

 only a fragment that can be examined, with respect to which it is un- 

 known to what height in the stalk it belonged. 



Palese of Ferns.* — Herr E. Goebeler describes the mode of develop- 

 ment and structure of the trichomes of ferns. They originate from older 

 segments of the apical cell of the stem, in which longitudinal, transverse, 

 and tangential septa have already been formed. Subsequently they may 

 develope either into a filament of cells constituting an ordinary hair, or 

 more commonly, by longitudinal divisions into a flat plate of cells, a wedge- 

 shaped apiculate palea or ramentum, the base occasionally remaining 

 unicellular. In some cases there is a central row of elongated cells, a rudi- 

 mentary mid-rib, which may even divide, by septa parallel to the surface, 

 into several rows of cells from which branches occasionally proceed ; in 

 Asplenium Trichomanes the mid-rib is especially well developed. The 

 margin of the palea is very commonly glandular or serrate ; much more 

 rarely is there a terminal gland. Only after the cells of the trichome 

 have attained their full development do their walls become brown and 

 thickened. Drops of oil and starch-grains are frequently found in the 

 protoplasm of the cells, but never chlorophyll ; in Struthiopteris germanica 

 there are numerous crystals of calcium oxalate. 



In the young frond the palese form a close felt, completely concealing 

 it, and forming a protection against mechanical injury, too much moisture, 

 and changes in temperature. They also especially serve as a reservoir of 

 moisture in the case of a large number of ferns which grow in dry situa- 

 tions or as epiphytes ; the tannin which they contain greatly assisting 

 in this. 



Pilularia.f — Mr. J. G. Baker completes his monograph of the Ehizo- 

 carpeae with a description of the six known species of Pilularia, the most 

 important distinguishing character being the number of cells into which the 

 conceptacle is divided. 



Muscineae. 



Reproductive Organs of Muscineae.| — Herr S. 0. Lindberg gives a 

 resume of the important points in the structure of these organs in Musci and 

 Hepaticse, viz. the inflorescence male and female, the archegonia, antheridia 

 and antherozoids, the calyptra, and the sporophore, composed of the 

 calceolus, which, buried in the disc of the inflorescence, serves to fix the 

 sporophore, and to absorb the nutriment required by the sexual plant, and 

 the capsule or theca with its spores. 



Peristome of Bryiim.§ — In the present portion of his ' Etudes sur le 

 peristome ' M. Philibert treats of those species of the section Cladodium 

 of Bryum, in which the ventral plates of the teeth show a tendency to 

 divide, by a larger or smaller number of accessory septa. These seem to 

 form a natural section, divided into two groups ; in the first the peristome 

 precisely resembles that of B. pendulum, the greater number of the ventral 



* Flora, Ixix. (1886) pp. 451-61, 476-81, 483-97 (1 pi.). 



t Journ. of Bot., xxiv. (1886) pp. 381-2. See this Journal, 1886, p. 1020. 



X Rev. BryoL, xiii. (1886) pp. 87-94, 100-9. 



§ Ibid., pp. 17-27, 81-6 ; xiv. (1887) pp. 9-11. 



