On the Prothallium of Phylloylossum. 285 



ammonium phospho-molybdate could be detected by the microscope. 

 A spectrographic analysis showed that these crystals were really beryls, 

 and similar crystals a millimetre in length were picked out of the 

 granite. They were found to contain between 10 and 11 per cent, of 

 beryllia. Since then beryllia has been separated from the alumina of 

 felspar obtained from the granite in Glen Cullen in proximity to a vein 

 of coarse granite in which beryls were found by Dr. John Joly. 



From numerous experiments on the analytical processes employed in 

 the separation of beryllia from alumina, it was found that it remained 

 combined with the sesquioxide bases in so persistent a manner as to 

 lead to the belief that ordinary alumina might be found more often 

 than not to contain traces of beryllia, particularly as there is no easily 

 applied chemical test for detecting its presence in small quantities, nor 

 a simple means of separating it. It has, however, been found that such 

 is not the case, though gallium has been ascertained to be present in 

 almost all minerals which contain aluminium. As they belong to the 

 same group, the two elements aluminium and gallium may be expected 

 to form isomorphous mixtures, which would account for their being so 

 constantly associated in nature ; but the position of beryllium in the 

 periodic system of classification shows that a similar behaviour with 

 that element is scarcely probable. 



" Preliminary Account of the Prothallium of Phylloglossum." 

 By A. P. W. THOMAS, M.A., F.L.S., University College, 

 Auckland, N.Z. Communicated by Professor Gr. B. HOWES, 

 F.E.S. Received October 31, Eead December 5, 1901. 



Our knowledge of the development of the Isosporous Lycopodinae is 

 still so incomplete that no apology seems necessary for the present 

 preliminary statement. A special interest attaches to Phylloglossum 

 since it has been recognised as a permanently embryonic form of 

 Lycopod.* Phylloglossum is a genus with a single species P. Dntm- 

 inondii confined to Australia and New Zealand. The sporophyte 

 generation is a small plant, growing from a tuber, which forms a tuft 

 of a few cylindrical tapering leaves. In fertile plants the apex of the 

 stem forms a peduncle, terminated by a cone or strobilus of small, 

 scale-like, fertile leaves. 



Treub has shown that the embryo of L. cernuum shows a remarkable 

 likeness to a barren plant of Phylloglossum, for the first formed leaves 

 have the character of the leaves of Phylloglossum ; hence the term 

 protophylls has been given to these structures, so different from the 



* Bower, ' Phil. Trans.,' 1886, p. 676. 



x 2 



