the author in a living condition, and also compared with specimens contained in various exsiccatæ and with the very extensive collection owned by Sir W. J. Hooker. The appearance of this book at once placed Berkeley in the front rank of Mycologists, and it was universally admitted as the most complete Mycologic Flora of any country extant; and furthermore, so far as accurate information, and a true sense of the conception of species are concerned, the same statement holds good at the present day. At this date our knowledge of extra-European fungi was almost nil, with the exception of a few woody cosmopolitan species collected by various travellers, more as matters of curiosity than for the advancement of our knowledge of the fungus-flora of the world.
Opportunity alone was required by Berkeley, and such opportunity was readily afforded by Sir W. J. Hooker, who placed unreservedly in Berkeley's hands the various collections of exotic fungi received at Kew from time to time. This practice was continued by the two succeeding Directors at Kew, Sir Joseph Dalton Hooker and Sir William Thiselton-Dyer. Such unrivalled opportunities were utilised to the fullest extent by Berkeley, who soon manifested by his treatment of the material placed in his hands a thorough grasp of the subject, and for nearly half a century practically all collections of exotic fungi passed through Berkeley's hands. During this period 6000 new species were described, and in numerous instances illustrated, including many new genera from all parts of the world, arctic, antarctic, tropical and temperate. Botanists were now enabled, for the first time, to grasp the true significance of the fungus-flora of the world, which numerically ranks next to Phanerogams, and which was shown to exercise an influence on life on the globe in general, not realised before Berkeley's time. The better known European genera of fungi, many of which appeared to be sharply defined, and by some mycologists considered to be of ordinal importance, could now be estimated at their true value and relegated to their true position in the scheme of classification rendered possible by a good knowledge of the range of structure presented by the fungi of the world at large. As regards geographical distribution, Berkeley repeatedly
