1888.] 



Aluminium in certain Vascular Cryptogams. 



123 



100 parts of ash con- 

 tained 



t * 



Al 2 O a - Si0 2 . 



* Ly copodium cernuum, Linn 16'09 30*25 



I found alumina (qualitatively) in the ash. of another member of 

 the L. cernuum group, namely, L. casuarinioides, Spring, from Mount 

 Ophir, Malacca, but the quantity of material at my disposal was too 

 small to admit of quantitative determination. So far my results were 

 strongly confirmatory of my conclusion that alumina was character- 

 istic of Ly copodium, and absent from Selaginella. But this opinion 

 was soon seriously shaken by an analysis of two exotic species of 

 Lycopodium, namely, L. Phlegmaria, Linn., and L. billardieri, Spring. 

 These plants were examined with the following results : — 



Percentage of ash 

 in dry plant. 



* Lycopodium Phlegmaria . . 4*08 



*L. Hilar dieri . 5*46 



On obtaining these results I abandoned the further prosecution of 

 the inquiry, it being obvious that alumina could no longer be regarded 

 as a characteristic ingredient of the ash distinguishing Lycopodium 

 from Selaginella. But when Mr. J. G. Baker's work on the ' Fern 

 Allies ' was published last year I turned to the classification of the 

 ninety-four species of Lycopodium there described, and found that 

 these last-named plants belonged to a group containing eighteen 

 species, all of which are epiphytic ! It was clear that, having no 

 direct access to the soil, these plants could obtain alumina only from 

 their living hosts, which in all probability contained none or mere 

 traces. The anomalous absence of this constituent from these two 

 Lycopodia was thus in a measure explained; at all events, it was 

 proved that alumina was not essential to all the species of this genus. f 



The present research was extended by examining plants more or 

 less closely related to the two genera under discussion. Following 

 the classification of Sachs (' Text-book of Botany,' edited by S. H. 



* The analyses, in the present paper, to which an asterisk is prefixed, have not 

 been previously published. 



f The occurrence of a high proportion of alumina in the mineral constituents of 

 those coals which give the smallest proportion of ash loses much of its significance 

 when the mode of the formation of coal is considered. It is impossible to feel sure thai 

 this ash is essential and not intrusive. The so-called Lycopods of the Carboniferous 

 Period are, moreover, now believed to belong to the Selaginacece. Of course it is 

 possible that many of the plants of that remote geological epoch may have 

 absorbed an element which their recent representatives refuse. 



100 parts of ash 

 contained 



A1 2 3 . SiO?. 

 0-45 — 

 trace 3" 14 



