514 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



on the strand, plains and mountain slopes. Two-thirds of the first are 

 species ubiquitous on tropical coasts. There are sixty-seven in all, thirty- 

 five being widely spread and abundant beyond the Malay Archipelago, and 

 many occur over the whole tropical zone. On the gently sloping beach 

 and on the sides of the mountain-cone there are forty-two, also being 

 of wide distribution. 



An interesting chapter is given on the biological conditions J on 

 Krakatoa. Every trace of the former vegetation had disappeared, and 

 the present flora is attributable to — ocean currents GO per cent., wind 

 32 per cent., and fruit-eating animals 7'5 per cent. Lizards, birds, gnats, 

 wasps, and red and black ants have also established themselves. The 

 first organisms were dark-green gelatinous layers of " blue-green " algae, 

 which were found on the surface of the pumice and ash. These were 

 regarded by Treub as affording a satisfactory nutritive medium for the 

 germination of the spores of cryptogams and the seeds of phanerogams. 



The question as to the necessary food for the plants, and the source 

 of nitrogen especially, is discussed, as well as the relative importance of 

 the different agents of plant dispersal in the colonization of the Krakatoa 

 islands. 



The work is a valuable contribution to the origin of a flora and its 

 ecological developments. 



" Handbook of Practical Botany, for the Botanical Laboratory and 

 Private Student." By Dr. E. Strasburger. Translated by W. Hillhouse, 

 M.A., &c. Sixth Edition revised. 8vo., 527 pp. (Swan Sonnenschein, 

 London, 1908.) 10s. Gd. 



We need scarcely say more than that this well-known book has been 

 brought thoroughly up to date. It is entirely devoted to microscopic 

 anatomy, and carries the student through the most characteristic features 

 of the leading groups of plants. Beginning with easy lessons, as that on 

 starch, he is led to karyokinesis of the nucleus, and shown how to examine 

 with reagents and all that is necessary. No student who has the time 

 required at his disposal could well do without the valuable aid afforded 

 by this excellent manual. 



" Systematic Anatomy of the Dicotyledons." By Dr. Hans Solereder. 

 Translated by L. A. Boodle, F.L.S., and F. E. Fritsch, D.Sc, F.L.S., 

 revised by D. H. Scott, M.A., F.R.S. Two vols. 4to., 1183 pp. 

 (Clarendon Press, Oxford, 1908.) 24s. net each volume. 



Apart from the interest which the minute anatomy of plants intrin- 

 sically possesses for the serious student, its value as an aid to the 

 determination of the natural relationships of plants has been demonstrated 

 by means of the active research with which it has been pursued during 

 the past few years, and it is of great importance as an assistance in other 

 lines of botanical investigation, both scientific and applied. The English- 

 speaking botanist therefore owes a great debt of gratitude to the author 

 who li;is amassed, and to the translators who have made more readily 

 available, the vast amount of information hitherto scattered through the 

 pages oi oiten inaccessible books and pamphlets. The original edition of 



