Page:Proceedings of the Royal Society of London Vol 69.djvu/301

Rh 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.

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.