NA TURE 



217 



THURSDAY, JULY 4, iJ 



CRYPTOGAMIC BOTANY. 



A Hand-book of Ciyptjgamtc Botany. By Alfred W. 

 Bennett, M.A., B.Sc, F.L.S., and George Murray, 

 F.L.S. With 378 Illustrations. (London : Longmans, 

 Green, and Co., 1889.) 



THE utility of a book presenting in clear outline the 

 present state of our knowledge of the morphology of 

 flowerless plants cannot be doubted. The division of plants 

 into Cryptogams and Phanerogams is, it is true, a non- 

 natural one. As the authors of this hand-book themselves 

 point out, the Vascular Cryptogams are "more nearly allied 

 in many respects to the Phanerogams than to the lower 

 Cryptogams." This fact, however, is not a serious ob- 

 jection to the limitation here adopted. If it is found 

 desirable, for teaching purposes, to treat the vegetable 

 kingdom in two divisions, the line maybe as conveniently 

 drawn between the Pteridophyta and the Gymnosperms 

 as anywhere else. The idea of a work dealing with the 

 families of Cryptogamic plants has been familiar to 

 English readers since the publication of Berkeley's famous 

 "Introduction to Cryptogamic Botany " in 1857. Since 

 that date the literature of the subject has accumulated 

 to an incalculable extent. A work of similar scope, 

 written at the present day, demands enormously increased 

 labour in compilation, and ofifers, perhaps, less room for 

 originality. In the authors' view, the object of the writer of 

 a hand-book is "to gather up and to collate material already 

 existing, winnowing, to the best of his judgment, the wheat 

 from the chaff." The indebtedness of the authors to their 

 predecessors is amply acknowledged, and it may fairly 

 be claimed for the hand-book that the arrangement of the 

 material is to a great extent its own. 



The descending order is followed throughout, the 

 Cryptogams being divided into seven groups : Vascular 

 Cryptogams, Muscineae, Characeae, Algae, Fungi, My- 

 cetozoa, and Protophyta. The reappearance of the 

 Characeae as a main group will be a surprise to those 

 who have become accustomed (and in our opinion rightly) 

 to regard them as green Algas. The Mycetozoa should 

 probably have been excluded altogether, and the Pro- 

 tophyta, as here limited, form a very heterogeneous 

 collection. On the other hand, we regard the breaking 

 up of the old sub-kingdom, Thallophyta, as a distinct 

 gain. The character on which it was founded is of 

 absolutely no systematic value, and the Alg^ and Fungi, 

 at any rate, are groups of sufficient extent and independence 

 to stand by themselves. 



The authors have introduced several changes in term- 

 inology. The most conspicuous, though not the most 

 important, of these is the adoption of Anglicized termina- 

 tions for Latin and Greek technical words. This is a 

 matter in which it is hard to draw the' line aright ; thus 

 we have already become used to " ovule " and " pistil " 

 instead of " ovulum " and " pistillum." But still, as a 

 matter of taste, we think the authors have gone much too 

 far in this direction. They complain of the " awkward 

 and uncouth foreign forms of these words " : we should 

 have thought this reproach applied much more strongly 

 to"coenobe," " sclerote," " nemathece," and "columel." 

 Vol. XL.— No. 1027. 



It need hardly be said that the authors themselves have 

 not succeeded in attaining consistency in this matter. 

 Happily, we are still allowed to say "prothallus" and 

 " nucleus," though "nucleolus" has become "nucleole," 

 and "gleba," "glebe." 



A more important point is the use of the word spore. 

 The authors define a spore as " any cell produced by 

 ordinary processes of vegetation, and not directly by a 

 union of sexual elements, which becomes detached for 

 the purpose of direct vegetative propagation." Thus the 

 word is used in a narrower sense than that of de Bary in 

 his " Fungi," or of Vines in his " Physiology of Plants." 

 The authors' use of the word seems in itself unobjection- 

 able, and is certainly preferable to Sachs's definition ; but 

 we do not see that anything is gained by the limitation 

 they propose. 



The substitution of " megaspore " for " macrospore " 

 we regard as an improvement, and only hope it may be 

 generally adopted. 



For sexual products the authors make use of the 

 termination " sperm " in the place of " spore," thus 

 speaking of zygosperms and oosperms. For the sake of 

 consistency they avoid using words compounded with 

 " sperm " for male cells ; thus " antherozoid " is once 

 more substituted for " spermatozoid," while "spermatium" 

 is replaced by " pollinoid." We cannot regard this last 

 name as a happy one, for it suggests a false comparison 

 with pollen-grains. As regards " spermatozoid " and 

 "antherozoid," the reasons on both sides seem very 

 equally balanced, though the former has the great ad- 

 vantage that it emphasizes the homology with the male 

 element in the animal kingdom. The term " spermo- 

 gonium " is abolished on the additional ground that the 

 "spermogone isa true antherid," a statement which, at 

 least in this general form, is really unwarranted by the 

 facts. The word " reproduction " is Hmited to " the pro- 

 duction of a new individual — that is, to a process of im- 

 pregnation." This definition seems to us to involve far 

 too much metaphysical hypothesis. 



The section on the Vascular Cryptogams is preceded 

 by some useful introductory remarks, in which the homo- 

 logies with the Phanerogams, and the general course of 

 development, are explained. The" statement that in apo- 

 gamy and apospory " either the oophyte or the sporophyte 

 may be entirely suppressed" is, however, inaccurate; as, 

 in the cases referred to, only the reproductive organs are 

 (wholly or partially) suppressed, and not the generation 

 which bears them. 



The Vascular Cryptogams are divided, as in the earlier 

 editions of Sachs's text-book, into a heterosporous and an 

 isosporous series. This arrangement is admittedly pro- 

 visional, but the difficulty in finding a truly natural 

 arrangement does not seem to us a sufficient reason for 

 adopting one which is manifestly artificial. 



The Rhizocarps are the class first described. The only 

 criticism of importance which suggests itself here is that 

 the clear relation of these plants to the isosporous Ferns 

 is insufficiently brought out. The other heterosporous 

 class is the widely different group Selaginellaceae, including 

 Selaginella and Isoetes. The following sentence (occur- 

 ring in the account of the latter genus) is very misleading : 

 " The mode of development of the megaspores presents 

 perhaps the closest analogy to that of. the secondary 



