Book Review

This book has many good points and some excellent ones. The main theme – dispersal biology, not just dispersal mechanisms! – is pursued throughout, sometimes with deliberate disregard of problems associated with comparative morphology, the emphasis being laid on the function of various adaptive mechanisms rather than on the semophyletic “origin” of these structures. Many recorded facts and observations, including several original ones, have never been compiled in this way before. The critical way in which the author discusses the older literature on the subject is another useful asset. The author’s personal experience with tropical and extratropical floras and theii different associated animal worlds adds local colour to his sometimes very refreshing and novel approach to the many problems of dispersal. It is gratifying to see that each form of dispersal is discussed in relation to various ecological factors, not every conventional category being treated as a single and invariable form of dispersal mechanism: geocarpy, for instance, treated on pp. 79-80, is not considered to be always an expression of “antidispersal” tendencies (atelechory) alone, but may have some other adaptive meaning (in Ficus it is associated with pollination by blastophagids, p. 23; in Cucumis humifructus with the antbear or aardvark, p. 46, etc.). A lucid explanation is given of the reasons why a classification of angiospermous fruits is bound to fail, because the various modes of dispersal mould the morphological features into a number of sometimes convergent dispersal types which often clash with a formal, morphological classification in terms of carpels, placentation, hypo- and epigyny, mode of dehiscence, etc. The new treatment of such stale subjects as anemochory, myrmecochory, epi- en endozoochory, barochory and autochory opens up several new perspectives and is certainly worth the attention of students of ecology. The discussion (on p. 36- 39) of the subject of “mimetic” seeds (and fruits), a kind of speciality of the author, is welldocumented and to me appears to be very convincing. All these good points make the book a “must” for taxonomists, ecologists, phytogeographers and even physiologists, both botanical en zoological ones, but also for more popular science libraries, for teachers and for use at the secondary school (and U.S. lower college) level. It is perhaps unfortunate that Dr. Van der Fiji has been co-author of two excellent books on flower pollination, because one is involuntarily inclined to compare his own more recent contribution with the other publications and finds some points of criticism which reduce its value to some extent. In the first place, many a physiologist reader will deplore it as an omission that although the emphasis is on ecology (as it should be), some more physiological aspects such as dormancy (especially “staggered” dormancy as an adaptive feature in arid regions), vernalisation, germination in light or in darkness, and the effect of inhibiting substances on germination (sometimes of temporary auto-inhibition), should have been treated in greater detail. Several reviews and compilations of these topics are available and a concise but penetrating discussion of the items concerned within the general framework of adaptive dispersal mechanisms would, in the reviewers opinion, have added to the value and scope of this book.