ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 321 



Ferns the structure of the leaf is Hable to be modified in the direc- 

 tion of the fihny character by conditions of moisture and shade. The 

 plants am-plojed were A^ephroi Hum FlUx-mas and Scolopendrium vulgare. 

 The results are described, and are shown in figures drawn with the 

 camera-lucida and placed side by side. They are less striking than 

 had been expected ; but better results were obtained by L. A. Boodle 

 with Ptoris aqnilina, and were published in vol. xxsv. of the Journal 

 of the Linnean Society. 



Morphology and Biology of Nephrolepis. — K. Goebel* gives the 

 results of his cultivation of Neplirolepis Dujfii, and concludes that it is 

 a mutation of N. cordifolia, as is shown by the reversion of its pinnas- 

 towards the shape characteristic of the latter species ; that neither this 

 nor any other fern-mutation can be regarded as the result of adaptation 

 to external conditions. He thinks that N. cordifolia may be a collective 

 species. 



E. Heinricherf has studied the tubers of Nephrolepis in Java, which 

 are situated on side-branches of the stolon of epiphytic plants, and serve 

 as water-reservoirs. He describes the circumstances under which they 

 may also act as organs of regeneration in iV. cordifolia subsp. tuherosa, 

 N. hirsutula, N. plumula var. phiUppinensis. They do not appear to 

 diminish tlie spore-production of the frond. They seem to him to be of 

 value for distinguishing species systematically. In sprouting the tuber 

 normally forms a stolon, but in certain circumstances it may produce a 

 rhizome. The stolons of Nephrolepis exhibit much plasticity, and can 

 develop into organs for food-storage, or into tubers ; and the same axis 

 can by artificial treatment be converted from a rhizome to a stolon with 

 distant leaves, and back again to a rhizome. 



Germination of Spores of Ferns and Mosses. | — A. Laage pub- 

 lishes the results of his researches upon the conditions affecting the 

 germination of the spores of ferns and mosses. After a short resume of 

 the work done by previous authors, he describes his own experiments, 

 which show inter alia that the capacity of a spore to germinate in dark- 

 ness depends entirely upon the age and the species. Osmunda regalis 

 differs from the rest of the score of species examined in its manner of 

 germination in the dark. Its spores, when fresh, will germinate in 

 distilled water at ordinary temperatures, and form starch, in the dark ; 

 but germination ceases after the splitting of the exine. The spores lose 

 the power of germinating in the dark after two months, and in the 

 light after four months. As to the spores of the Polypodiacese, their 

 power of germination in the dark varies greatly according to the 

 species. This power, very marked in Pteris aqiuUna and Scolopen- 

 drium officinarum, is, on the other hand, quite absent in Asplenium 

 lucidum, Alsophila austral is, and Polypodium aureum; none of the 

 species experimented with form starch. The author treats of the 

 relation between the formation of rhizoids and of the germination- tube, 

 and describes the constitution of the nutrient fluids employed. As. 



* Flora, xcvii. (1907) pp. .38-42 (figs.). 



t Tom. cit., pp. 43-75 (2 pis. and tigs.). 



X Beih. Bot. Centralbl., xxi. Abt. 1 (1907) pp. 76-115 (figs.). 



