3i8 SCIENCE PROGRESS 



A general account is given of the researches on movement and growth, 

 and the author succeeds in doing what he had intended, namely, effectively, 

 but not exhaustively, covering all the ground. He gives an accurate and 

 clear account of the results achieved, but does not seem so happy in his 

 attempts to connect these interpretations with those of other workers in 

 the field. For example, the results of observations on the " Praying Palm " 

 are given, and we are told that similar movements have been observed by 

 Professor Bose " in all trees and their branches and leaves " ; but no reference 

 is made to the large amount of scattered literature, dating from about 1842, 

 on the subject of the connection between temperature and the movements 

 of branches ; and on p. 176 there is confusion of thought between perception 

 and response, both in the case of gravity and of light. 



The importance of Sir Jagadis Bose's work is now generally admitted, 

 and as recently as May of this year he was elected to a Fellowship of the 

 Royal Society. In 1917 he saw the dream of his life realised on the opening 

 of the Bose Institute. Two important volumes of botanical researches have 

 already been published, and we are told that in the near future other branches 

 of learning will receive attention from the workers in the institute. The 

 biography, if not a great one, is at least very competent and reliable. 



E. M. C. 



New Zealand Plants and Their Story. By Prof. L. Cockayne, Ph.D., F.L.S., 

 F.R.S. New Zealand Board of Science and Art Manual, No. i. 

 [Pp. XV + 248, with 99 photographic illustrations and 14 text-figures.] 

 (Wellington, 1919.) 



The Flora of New Zealand is one of the most interesting of the island Floras 

 of the world, of which no one is more competent to tell the story than Prof. 

 Cockayne. Like all areas isolated by natural barriers, that prevent or 

 retard the gradual process of dispersal, New Zealand possesses a large pro- 

 portion of endemic species, some of which — as, for example, Pittosporuni 

 obcordatum — are amongst the world's rarest plants. Of the vascular plants, 

 the endemics comprise 74 per cent., whilst amongst the Dicotyledons and 

 Conifers together their proportion rises to 85 per cent. 



Much has been said and written with regard to the success of the intro- 

 duced species, of which no less than 520 have become securely established. 

 But the author strongly emphasises the fact that it is only where the inter- 

 ference of man has modified the conditions of the habitat that there is any 

 evidence of the success in competition with the native Flora to which so 

 much prominence has been given. " With but one trifling exception, no 

 truly primitive plant-formation is desecrated by a single foreign invader." 



It is the human factor which has been responsible for so much change, 

 and in particular for the deterioration of the mountain pasture, which now 

 only supports one sheep for every four acres. 



The successive chapters describe the various types of vegetation in an 

 attractive manner, unusually free from the assumption of any but the most 

 elementary technical knowledge. Much of the information thus conveyed 

 is of a general character, and equally applicable to our antipodean Flora. 

 The Dune Vegetation, for instance, is essentially similar to our own in its 

 physiognomic character, and even in the specific identity of some of its con- 

 stituents. Spinifea serves as the New Zealand Psamma, whilst Convolvulus 

 soldanella plays the same role as with us. So too Zostera nana covers the 

 mud of shallow estuaries along the edge of which occurs the tidal scrub 

 dominated by Avicennia officinalis, and salt marshes with Scirpus ameri- 

 canus, Leptocarpus simplex, Juncus maritimus, V. australiensis, Salicomia 

 aiistralis, etc. 



The forests contain a large number of diverse trees, but nevertheless 



