84 SUMMARY OF CUBKENT RESEARCHES RELATING TO 



the spore-measurements, calling attention to the vitality and floating- 

 capacity of the spores, which for germination require good light ; in 

 cultivating them he succeeded best by employing their native mud, and 

 he noticed that the fronds arranged themselves parallel to the incident 

 light. He describes the first stages of development, in which he could 

 find no trace of an apical cell. Gemmre he found in the Central Asiatic 

 E. Paulsenii ; these rise to the surface, and float until their stores of fat 

 are used up in growth. As the result of germination of spores, gemmae, 

 etc., a primordial lobe (protonema) is produced, the growth of which 

 ceases at the apex, and a meristematic growing-point is formed near 

 the base at one or both edges, which as it develops pushes aside the 

 primordial lobe and forms on one side the stem and leaves, and on the 

 other the dorsal wing and reproductive organs. In species of vertical 

 habit, the stem and dorsal wing are from the first vertical. The growing 

 point is thus intercalary and meristematic. As a general rule there is 

 no apical cell, even up to a late stage ; sometimes, however, in strongly 

 developed plants of the larger species, a wedge-shaped apical cell occurs 

 at the point of junction of stem and wing, and throws off segments 

 upwards to the wing and downwards to the stem, but only the wing- 

 segments can be recognised for any length of time. The normal 

 absence of an apical cell indicates the primitive character of the genus. 

 The oil-bodies situated along the margin of the frond possibly serve to 

 protect the plant from being eaten by animals. No fresh details as to 

 the reproductive organs were observed, but in the sporogonium some 

 of the cells which fail to become spore-mother-cells persist as stores of 

 starch. As to the E. Jhelkophylla, the beautiful helicoid growth figured 

 in the Flore (V Alger ie is no exaggeration, and may be a result of growth 

 in subdued light in deep w 7 ater (Goebel) ; and the tufts of rhizoids 

 shown as springing from knots at the base of the stem are germinations 

 from spores in semi-decayed sporangia. E. Parisii, a floating species, 

 is peculiar in its habit. 



Riella capensis sp. n.* — F. Cavers describes and figures this new 

 species, obtained from dried mud, which had been gathered from a pond 

 at Port Elizabeth for the sake of the Crustacea contained in it, and 

 sent to the Owen's College, Manchester, for cultivation in an aquarium. 

 The plant soon made its appearance, and in three months' time was 

 found to be in a fruiting state. It is allied to /.'. helieophylla, but 

 sufficiently distinct. The author gives full details as to its habit. 



Petalophyllum Ralfsii.| — F. Cavers gives a full description of this 

 very rare hepatic, wdiich occurs sparingly in patches of Pallavkinia on 

 Coatham Marshes, Yorkshire. It has been gathered only in five British 

 and one Italian locality, and always in damp sandy places near the sea. 

 It may prove to be identical with the Algerian Fossombronia corbulce- 

 formis. The author describes in detail and figures the structure of the 

 gametophyte, and calls attention to the marked occurrence of mycorhiza 

 in the ventral zone of the thallus, and to the formation of tubers much 

 resembling those described in the Californian Geothallus tnberoxus. 



'& 



* Etev. Brvol , xsx. (1903) pp. 81-4 (1 pi.). 



f The Xatuialist, 11)03, pp. 327-34 (li-s. in text). 



