Aii§: 20, 1874] 



NA TURE 



305 



interest it is necessary to be instructed ; and in an immense 

 number of cases it is impossible to convey in non-techni- 

 cal language, so as to be understood by the uninstructed, 

 in what the interest consists. Hence it follows that a 

 large number of scientific workers have conceived a de- 

 cided contempt for all attempts to popularise science. 

 Their_"position is so far sound. Still, it is extremely im- 

 portant in the interests of science itself that its investiga- 

 tions should not be wholly withdrawn from the notice of 

 the general community and confined to a small esoteric 

 class. Here the function of the evangelists needs to be 

 properly recognised ; we want men with Dr. Macmillan's 

 sympathy with the subject-matter and liking for ex- 

 position to take a wider view of it in respect to 

 general interest than it will ever be possible for the special 

 student to take. If public funds are to be devoted to 

 scientific purposes, it is absolutely necessary that the 

 public mind should have some idea that they are being 

 expended on something of more general importance than 

 individual hobbies, as they will be too apt to believe, un- 

 less their sympathy with the work is occasionally kindled. 

 It is not every branch of science which is capable of 

 yielding results which can at once be turned to commer- 

 cial profit, and though knowledge in every line of investi- 

 gation may be expected to yield practical applications in 

 the most unexpected directions, it would be an evil 

 lir.ic for scientific advancement when the community 

 determined to shut its eyes and close its ears to everything 

 which could not be shown to pay. It is very likely, how- 

 ever, to begin to do this unless scientific men take mea- 

 sures to excite intelligent interest where there is no obvious 

 suggestion of profit to gratify the natural cupidity of a 

 commercial country. 



It is worth while making these remarks, because it de- 

 serves to be borne in mind that the v.'ork — though apt to 

 be contemned — is not easy to do ; nor is it easy to find 

 men fit to do it. And the criticisms which we shall now 

 proceed to make on Dr. Macmillan's book are made by no 

 means from a desire to find fault, but rather to bring into 

 prominence the inherent difficulty which exists in writing 

 such a book as it should be written. If the author has 

 not had a thorough drilling in the technicalities of 

 the subject, then, as Dr. Macmillan has done, he will make 

 some exceptionable statements and stray into sundry 

 grievous pitfalls. If, on the other hand, he is quite and 

 fully competent to write the book, it is tolerably certain 

 lie will never write it at all. The general reader wants 

 his science skimmed for him — and this is an operation 

 which a competent student particularly dislikes to perform. 



It is a pity that some of Dr. Macmillan's friends ''whose 

 scientific position lends weight to their opinions " did not 

 assist him in issuing the work in its new form. This in 

 fact seems to be the only chance of doing the thing 

 properly. The aid of those who would not actually write 

 such books might at any rate be given for the purpose of 

 keeping them free from glaring blunders. 



Mosses, for example, we are told (p. 27) belong to the 

 highest division of flowerless plants. This statement can 

 only be met by a categorical negative. As to their being 

 "prefigurations of the flowering plants, epitomes of arche- 

 types in trees and flowers," if this is the alternative for 

 technical language, the general reader can hardly be con- 

 gratulated on the change. But the author seems not to have 



a very clear conception of the structural rank of mosses. He 

 tells us on the next page that "through the cone-like spikes 

 of the club-mosses they approximate to the pine tribe in 

 their fructification." This is a rapprochement which no 

 modern systeraatist would think of making. In fact, 

 mosses and club-mosses have the same kind of relation- 

 ship and no more that ants have with white ants or the 

 albumen of an egg with the albumen of a seed. 



On p. 37, it takes one's breath away to read, ''Besides 

 these curious capsules there are other organs of fructifi- 

 cation which clearly demonstrate the sexuality of mosses." 

 It hardly at first occurs to the reader that the author 

 has no notion that the capsules are really the fertilised 

 product derived from the sexual apparatus. The cap- 

 sule — and this is one of the most remarkable things 

 in the whole vegetable kingdom — is gradually developed 

 from the oospore ; its being composed of modified leaves, 

 as Dr. Macmillan explains on p. 40, is an antiquated 

 idea. There is something indeed to strike an intelli- 

 gent curiosity on almost every page. At p. 80 we 

 are told of Lycopods " becoming slightly arborescent 

 in tropical countries, particularly New Zealand." On 

 p. 84 "some species" are said "to have little cone- 

 like spikes at the tips of their branches under the 

 scales of which, as in the pine tribe, lurk the re- 

 productive embryos." This is simply utter nonsense. 

 In so far as the process is understood we have spores 

 borne in spore cases at the base of the upper surface 

 of the fruiting scales, and these spores when dissemi- 

 nated undergo a further process of development, which 

 results in the formation of an embryo. 



Dr. Macmillan dismisses Schwenderer's theory of 

 lichens in a very ex cathedra fashion. En revanche, he is 

 equally decided in rejecting Dr. Bastian's views on 

 heterogenesis. 



We regret that this book has not been put into a more 

 satisfactory shape, for the author has industriously col- 

 lected a great deal of very interesting matter. 



W. T. T. D. 



LETTERS TO THE EDITOR 



\Tlie Editor does not hold himself responsible for opinions expressed 

 by his correspondents. No notice is taken of anonymous 

 com munications .] 



Bright Meteors 



On .Saturday last I saw live very bright meteors, each coming 

 fiom the Perseus radiant point, and isolated from smaller ones 

 by such a length of time that my (possible) watch error of per- 

 haps one minute will not prevent their being identified if they 

 hive been observed at other stations. 



A very bright one, almost like a rocket, passed exactly over 

 Vega at 10.35. 



Another, nearly as bright, passed through the intersection of 

 the diagonals of the quadrilateral of Mouoceros at 10.55. 



r. G. Tait 



St. Andrew's, N.B., Aug. 13 



Mr. Herbert Spencer and Physical Axioms 



I CANNOT help thinking that something of importance still 

 remains to be said on the subject of the laws of motion, recently 

 argued in your columns with so much ability by Spencer, Tait, 

 and others. 



There are three species of magnitude, viz. , number, extended 

 magnitude, and magnitude of degree. Magnitude of degree ad- 



