138 NATURAL SCIENCE. August. 



sitional form between Hysteranghim and Clathrus, thus confirming the 

 view, held by some previous students of the group, that Clathrus and 

 its alhes had developed from the more primitive form. The other 

 genera, Blumenavia, Apovophallus, and Itajahya belong to the highly- 

 organised Phalloidecs. MoUer has been led to dignify them with the 

 title " Pilzblumen " (fungus flowers), on account of the striking 

 odour, pleasant or otherwise, which they exhale, and also on account 

 of the colours and forms displayed by the different species, which 

 serve to attract insects, and so aid in the dissemination of the spores. 



A. L. S. 

 Lunar Physiography. 

 The Moon : A full description and map of its principal physical Features. By 



Thomas Gwyn Elger. 8vo. Pp. viii-173, with 4 maps. London ; Geo. 



Philip & Son. Price 5s. Map issued separately as whole sheet, 2s. 68. 



A CHEAP concise handbook to the moon has long been a desideratum, 

 for no member of the solar system is more interesting, is more 

 convenient of study or affords better training to the young astronomer 

 than what the Irish ballad calls the " fine noble creature, which gives 

 us the daylight all night in the dark." The works of Neison, Beer 

 and Madler, Schmidt, Nasmyth, etc., were either too expensive or 

 somewhat out of date. A popular summary of the whole question of 

 lunar physiography may, therefore, be expected to be of value to the 

 increasingly numerous class of men who possess telescopes of sufficient 

 power to aid in the work of mapping its surface. To these, Mr. Elger's 

 book can be confidently recommended. It is concise, cheap, clear, and, 

 as far as we have tested it, correct. It is conveniently arranged. It 

 commences with a description of the different " earth-forms," which 

 can be recognised on the moon, such as the great plains or " Maria," 

 ridges, ring mountains, including craters, walled plains and crater pits, 

 clefts or rills, and valleys. The exact significance of these different 

 forms is discussed, and most of the principal theories are referred to. 

 The two principal omissions which we notice in the literature is that 

 there is no reference to the remarkable paper by Gilbert, and the still 

 more recent one of Suess. The part of the work which discusses 

 lunar geology is the least satisfactory, for the author's knowledge 

 of the earth is not so well up to date as is that of the moon. 

 This is unfortunate ; for the impression is certainly growing that the 

 explanation of lunar topography will come from the study of the 

 geology of the great continental volcanic areas. It is useless, there- 

 fore, to quote men such as Professor Phillips, Avho wrote before the 

 volcanic region of the Western States had been described. Mr. Elger, 

 nevertheless, seriously discusses Phillips' comparison of the lunar 

 ridges to kames and eskers, while his information on these is 

 antiquated, for he says these are " of somewhat doubtful origin," and 

 quotes one explanation of them to the effect that they are " old sub- 

 marine banks formed by tidal currents like harbour bars." We 

 should have been glad, moreover, if he had indicated the differences 

 between the lunar rills and terrestrial canons, and not simply 

 dismissed the question by the remark that " the analogy, at first sight 

 specious, utterly breaks down upon closer examination." We would 

 venture to remind the author that canons are not all due to the same 

 cause as that which made the Grand Canon of the Colorado. 



The main part of the work is occupied by a catalogue of the 

 lunar formations, those of the four quadrants being taken separately. 

 Appendices give lists of the maria, mountains and ray systems, a table 

 of lunar elements, and an alphabetical index to the formations. 



