ZOOLOGY AND BOTANY, MICEOSCOPY, ETC. 681 



whether through the leaves or in the nutrieDt solution through the 

 root ; any one of these modes being in opposition to well-attested 

 experiments. A possible explanation seems to be that free nitrogen 

 is absorbed by decaying vegetable substances by the assistance of 

 electricity. 



B. CRYPTOGAMIA. 

 Cryptogamia Vascularia. 



Affinities of Laccopteris.* — The genus Laccopteris is formed of 

 several species of fossil ferns the remains of which are found in 

 strata from the Ehtetian to the Cretacean, and has been referred to the 

 Gleicheniaceae. This distribution is confirmed by M. E. Zeiller, who 

 points out that the structure of the sporangia is almost identical with 

 that in Matonia. The sori are composed of from 5-11 large sporangia, 

 arranged in a stellate manner, differing only from those of Matonia in 

 the absence of the membranous indusium, which may not be constant. 

 The sporangia are furnished with a large complete oblique annulus. 

 The spores have the same tetrahedral form. 



Composition of the Ash of Equisetaceae, and its Bearing on the 

 Formation of Coal.f — M. Dieulafait has examined 168 samples of the 

 ash of various existing species of Equisetacefe collected in different 

 localities. Although the ashes of different species vary considerably 

 in composition, they are all characterized by the presence of calcium 

 sulphate in large excess, and the total absence of alkaline carbonates. 

 The proportion of ash varied from 5'2 to 8*3 per cent, of the fresh 

 plant, and the mean amounts of potassium sulphate and calcium 

 sulphate in the ashes were 12 "0 per cent, and 14*3 per cent, respec- 

 tively. The mean percentage of sulphuric acid was 13 '91, whilst 

 the amount of this acid in the ashes of other plants collected in the 

 same places was not more than 1 per cent. These latter ashes also 

 contained a large proportion of alkaline carbonates. 



The presence of such large quantities of sulphuric acid in the 

 Equisetaceaa is obviously one of the causes of the presence of sulphur 

 in coal. 



Transitional Equisetum4 — Herr A. Topffer describes an Equi- 

 setum found at Gastein intermediate between E. variecjatum and E. 

 acirpoides, agreeing in all respects with E. variecjatum var. anceps, but 

 possessing the peculiar " root-felt " of ^. scirpoides. 



Muscineae. 



Conduction of Water in the Stem of Mosses. § — Dr. G. Habcr- 

 landt replies to the observations of Herr F. Oltmanns || on this subject. 

 He objects to the experiments of the latter on Mnium that he allowed 

 the plant to become too dry ; and contends that the central bundle is 

 the organ by means of which the plant raises water out of the soil. 



* Bull. Soc. Bot. Franw;, xxxil. (1885) pp. '21-5 (1 fig.). 



t CoinptoH KeiKluH, c. (1885) pp. 284-G. 



X OcHtcrr. Bot. ZeitHclir., xxxv. (1885) pp. 121-2. 



§ Bor. lJcuti<;h. Bot. (Jo.scll., ii. (1885) pp. 407-71. 



II 8co tJiiu Journal, nuU', p. i'J'd, 



