February io, 1898] 



NATURE 



339 



It is disappointing to find that no mention is made of 

 the gametophyte in ascertaining the relations of the 

 classes to one another ; although its systematic value 

 has been shown in several cases. It is quite possible 

 that the position of doubtful genera, such as Loxsoma, 

 will only be understood when its gametophyte has 

 received complete investigation. The omission, how- 

 ever, may be justified owing to the practical difficulties of 

 obtaining the sexual generation for systematic purposes. 



The introduction is short and is chiefly occupied with 

 explaining the scope of the book ; and it seems a pity 

 that a writer, with so much knowledge of the ferns, did 

 not give more space in his work to general considera- 

 tions. At the end, however, Dr. Christ refers to the 

 marked manner in which ferns belonging to different 

 classes resemble one another : thus, Diacalpe — a member 

 of the Aspidiaceae — has a sorus very like that found in 

 the Cyatheaceas. In the Polypodiaceae some genera 

 have the sorus situated at the tip of the veins and 

 projecting beyond the margin of the leaves, in this 

 reminding us of the HymenophyllacCce. It is fanciful, 

 if not inaccurate, to see in this position of the sorus a 

 resemblance to the mosses. Other interesting examples 

 are given ; but it is unfortunate that the author applies 

 the term "mimicry" to these instances of parallelism in 

 related groups. Such an application of the term must 

 only lead to confusion. 



The descriptions of the genera and species are marked 

 by their precision and lucidity, and the numerous illus- 

 trations, which were specially prepared for this work, are 

 characteristic drawings, though sometimes roughly ex- 

 ecuted. The appearance of such a book will be welcomed 

 by systematists interested in the ferns containing, as it 

 does, the more recent results of Baker, Hooker, Kuhn, 

 Luersson, Prantl, &c., and those of Dr. Christ himself. 



It might be suggested that if the key of genera, which 

 precedes the detailed diagnoses of genera and species, 

 was furnished with references to the pages on which the 

 diagnoses are to be found, an addition would be made to 

 the usefulness of the book. H. H. D. 



SCIENCE IN FICTION. 



The War of the Worlds. By H. G. Wells. Pp. 303. 

 (London : William Heinemann, 1898.) 



MANY writers of fiction have gathered material from 

 the fairy-land of science, and have used it in the 

 construction of literary fabrics, but none have done it 

 more successfully than Mr. H. G. Wells. It is often 

 easy to understand the cause of failure. The material 

 may be used in such a way that there appears no 

 connection between it and the background upon which it 

 is seen ; it may be so prominent that the threads with 

 which it ought to harmonise are thrown into obscurity ; 

 or (and this is the worst of all) it may be employed by 

 a writer whose knowledge of natural phenomena is not 

 sufficient to justify his working with scientific colour. 

 Mr. Wells makes none of these mistakes. Upon a 

 groundwork of scientific fact, his vivid imagination and 

 exceptional powers of description enable him to erect a 

 structure which intellectual readers can find pleasure in 

 contemplating. 



NO. 1476, VOL. 57] 



"The Time Machine" — considered by the majority of 

 scientific readers to be Mr. Wells' best work— showed at 

 once that a writer had arisen who was not only familiar 

 with scientific facts, but who knew them intimately 

 enough to present a view of the future. "The Island 

 of Dr. Moreau," though decried by some critics, is a 

 distinctly powerful work, and the worst that can be said 

 of it is that the pabulum it provides is too strong for the 

 mental digestion of sentimental readers. But in several 

 respects " The War of the Worlds " is even better than 

 either of these contributions to scientific romance, and 

 there are parts of it which are more stimulating to 

 thought than anything that the author has yet written. 



The invasion of the earth by inhabitants of Mars is 

 the idea around which the present story is constructed 

 The planet is, as Mr. Percival Lowell puts it, older in 

 age if not in years than the earth ; and it is not un- 

 reasonable to suppose that if sentient, beings exist upon 

 it they would regard our world as a desirable place for 

 occupation after their own globe had gone so far in the 

 secular cooling as to be unable to support life. Mr. 

 Wells brings the Martians to the earth in ten cylinders 

 discharged from the planet and precipitated in Surrey. 

 The immigrants are as much unlike men as it is possible 

 to imagine, and only a writer familiar with the lines 

 of biological development could conceive them. The 

 greater part of their structure was brain, which sent 

 enormous nerves to a pair of large eyes, an auditory 

 organ, and sixteen long tactile tentacles arranged about 

 the mouth ; they had none of our complex apparatus of 

 digestion, nor did they require it, for instead of eating 

 they injected into their veins the fresh living blood 

 of other creatures. Their organisms did not sleep any 

 more than the heart of man sleeps ; they multiplied by 

 budding ; and no bacteria entered into the scheme of 

 their life. When they came to the earth they brought 

 with them a means of producing a ray of intense heat 

 which was used in connection with a heavy vapour 

 to exterminate the inhabitants of London and the 

 neighbourhood. 



This bald outline does not, however, convey a good 

 idea of the narrative, which must be read before the 

 ingenuity which the author displays in manipulating 

 scientific material can be appreciated. The manner in 

 which the Martians are disposed of is undoubtedly the 

 best instance of this skill. As the Martians had eliminated 

 micro-organisms from their planet, when they came to 

 the earth their bodies were besieged by our microscopic 

 allies, and they were destroyed by germs to which natural 

 selection has rendered us immune. This is a distinctly 

 clever idea, and it is introduced in a way which will 

 allay the fears of those who may be led by the veri- 

 similitude of the narrative to expect an invasion from 

 Mars. Of course, outside fiction such an event is hardly 

 worth consideration ; but that the possibility of it can be 

 convincingly stated, will be conceded after reading Mr. 

 Wells' story. A remarkable case of the fulfilment of 

 fiction is furnished by the history of the satellites of 

 Mars. When Dean Swift wrote "Gulliver's Travels" 

 (published in 1726), he made the astronomers on the 

 island of Laputa not only observe two satellites, but 

 caused one of these to move round the planet in less 

 time than the planet itself takes to rotate on its axis. 



