NA TURE 



\_March 27, il 



got answers from Prof. Sylvester's infinitely thin book- 

 worm . 



If the examination-system is to be maintained without 

 being on tlie one hand hopelessly discredited, or on the 

 other lapsing into a kind of ceremonial observance like 

 academic dress or a Guy Fawkes celebration, something 

 must seriously be done to ascertain the real relation 

 between A and A'. It is generally presumed that the 

 object of "plucking "a candidate is to indicate to him 

 his imperfect knowledge. But though the student of the 

 subject c.'iUed A' is usually plucked by the examiner in A 

 it is not clear that what may be called the moral result is in 

 any way satisfactory. The examiner is disgusted equally 

 with the candidate who has likely enough done his very 

 best, just as the infinitely thin book-worm might do his 

 best. The candidate grinds away at his A' with more 

 assiduity than ever if he is modest enough to think his 

 ignorance to be in fault ; but this only makes his subse- 

 quent failures with the examiner in A more assured, 

 because the radical incommensurability of A and A' 

 becomes more intensified. 



There is really reason to think that underneath the 

 rational fabric of science as understood by intelligent 

 persons of common sense there is a vast substratum of 

 something altogether different, but with which a large num- 

 ber of individuals are quite seriously occupied. A' is only 

 a term in fact of a very considerable series. Every now 

 and then in the pages of this journal strong evidences 

 crop up of the existence of this singular body of know- 

 ledge. This existence, however, is scarcely really grasped 

 by the scientific world proper, and it might be compared 

 to a sort of inverse of Prof. Tait's unseen universe. 



The present state of things can hardly go on. It is 

 quite certain that, whatever intrinsic interest science of 

 the A' type may possess, it is of no kind of practical use 

 to ordinary human beings. If it cannot be displaced by 

 the real thing of which it is a kind of phantom, it is a 

 serious question whether the struggle of the examination- 

 room had better not be for a time suspended. 



In the meantime it is very important to investigate the 

 true nature of this phantom science. A little work, of 

 which the second edition has been lately sent to this 

 journal for review, appears to belong to its literature, 

 which there is reason to think is rather copious. This 

 particular publication is part of the " Students' Aids 

 Series," bears the motto, " Mc>!S sana corjiore sano,'' and 

 deals with botany. ' It is impossible to seriously criticise 

 it ; indeed, from the point of view of what has been said 

 above it would not be easy to do so. We may content 

 ourselves with reproducing textually from its pages the 

 entire account given of a well-known and very characteristic 

 group of Thallophytes : — 



THE OLIVE SEAWEEDS. 



These weeds vary in general appearance from small 

 tufted filaments to immense stalks terminated by a 

 branched thallus. 



' " Aidsto Bjtany." By Armand Semple, E. A , M.B., Cainab. ; L.S.A , 

 M. R.C.P.. Liiid , Pnysic'.an North-Eastern Hospital for Children, Hackney, 

 Physician ti the Royal Society of Musicians, late Senior Examiner in Arts 

 at .\pothecaries' Hall, late Medical Clmical Assistant and Surgical Registrar 

 at the Lond-)n Hospital, author of the " Esscnt.al Features of Diseases of 

 Children,'* " Aids to Chemistry "(Inorganic and Organic), " Aids to Materia 

 Medica" (Inorganic and Organic), "Tablets of Materia Medica,*' "Aids 

 to Medicine." (D mble Part ) Third Thousand. (London : Bailliere. Tindall, 

 and Cox, King William Street, Strand. Dublin : Fannin and Co , Grafton 

 ' Street. Edinburgh : MacLachlan and Stewart, South Bridge. Glasgow : 

 A. and W. Stenhouse, College Gate. New York : Putnam and Sons, 1883.) 



In the higher forms a shrubby aspect, a kind of root, 

 and an epidermal layer are observed. Their colour is not 

 bright green, but in general olive. 



The zoospores originate in Oosporangia, situated at 

 ends or joints of the frond, or in each ot the cells of a 

 fil.imentous body called a Trichosporangium. ; they 

 resemble those of the Green Alga;. 



The zoospores from the Trichosporangium have been 

 mistaken for spermatozoids. 



The spores reside in sics termed Perispores, having a 

 lining membrane, the Epispore. 



The perispores or sporangia are either scattered or are 

 arranged in Sori or groups on the frond's surface, or in 

 cavities, Scaphidia or conceptacula, communicating by 

 a pore with its surface. 



The scaphidia may appear as club-shaped masses or 

 receptacula at the edges of the frond. 



The antheridia are ovate sacs which contain Anthe- 

 rozoa or Phytozoa (two ciliated spermatozoids), and 

 appear on slender filaments in the same or other plants, 

 and in the same or other conceptacles as the spores. If 

 on the same plant, they are called Moiioecious ; if on 

 different, Dicecious. When in the same conceptacles 

 with the spores, they are Hermaphrodite. To the slender 

 filaments destitute of antheridia the name of Paraphyses 

 is given. 



We must leave to our botanical readers to notice for 

 themselves where this instructive specimen of A' science 

 differs from the kind of lesson which an ordinarily con- 

 stituted teacher of real botany would try to communicate 

 to his pupils. At any rate we may ask, would any one 

 having learnt all this by rote (for there is reason to think 

 that such is the method insisted upon) be secure in recog- 

 nising a piece of bladder wrack when shown to him, or 

 certain of any single fact in its life-history. 



A curious point about the A' science is the copiousness 

 and more or less unintelligibility of its terminology. 

 There is no doubt, however, that this is very generally 

 mastered, however repulsive such a task might seem at 

 first sight. But the problem is still unsolved as to what 

 is the end gained. With the same effort it is probable 

 that the rudiments of an Oriental language might be 

 acquired — say Arabic — and the question arises whether 

 in every way this would not be more profitable. 



LEFROY'S MAGNETIC SURVEY IN CANADA 

 Diary of a Magnetic Survey of a Portion of the Dominion 

 of Canada, chiefly in the North- Western Territories, 

 Executed in the Years 1842-44. By Lieut. Lefroy, R.A., 

 now General Sir J. H. Lefroy, C.B., F.R.S., &c. 

 (London: Longmans and Co., 1883.) 



THIS record of magnetical work performed forty years 

 ago by Lieut. Lefroy of the Royal Artillery — now 

 General Sir J. Henry Lefroy — is a contribution of interest 

 to the science of terrestrial magnetism. 



The Magnetic Survey of the British Possessions in 

 North America authorised by Her Majesty's Government 

 in the year 1841 at the recommendation of the Royal 

 Society, and in great part executed in 1S43 and 1844 

 under the supervision of the late Sir Edward Sabine, had 

 for its primary objects the determination of the regular 

 and irregular changes of the magnetic elements, especially 

 that of the horary variation of the declination ; this varia- 

 tion being then known as subject to wide differences in 

 the high magnetic latitudes of the northern hemisphere 



