Sept. 1 6, 1S75] 



NATURE 



445 



Porpoise), three inches long (as if extended), lent to Prof. 

 Wilder by Mr. Alex. Agassiz, Curator of the Museum of Comp. 

 Zoology at Cambridge. The last two specimens are believed to 

 be the smallest of their kind hitherto recorded. 



Prof. Wm. S. Barnard, of Canton, 111., read a paper On the 

 Detiflopmmt of the Opossum, Didelphys virginiana. — Prof. Bar- 

 nard read another paper, in which he compared the muscles of 

 man with those of the higher apes, showing the points of simi- 

 larity as well as of difference. An interesting point made in 

 this paper was the statement that one of the buttock muscles 

 supposed to be peculiar to the higher apes, distinguishing them 

 from man, really existed in the human body and in a similar 

 position. It was shown that the muscle thus described by Traill, 

 and afterwards by Wilder as in the chimpanzee, and by Owen and 

 Bischoff as in the orang, and by Coues as in the opossum, is also 

 found in man, and offers no distinction in this respect. Three 

 new muscles about the hip-joint, found in the orang and some 

 other apes, were also made the subject of description ; these 

 muscles have no homologues in man. Two of these act to rotate 

 the leg and draw it inward ; the other seems too small to have 

 any functional value and is probably a rudiment, but is interest- 

 ing as occurring also in some of the lower apes and the opossum. 

 The other muscles in this region of the body w^ere like those of 

 man, but in the case of an orang the short head of the biceps of the 

 thigh was found entirely separated. This is only occasionally the 

 case with the orang, and this peculiarity is not known to exist in 

 any other animal. The two large external muscles of the calf 

 do not unite with each other to form a single tendon Achillis, 

 consequently in the orang this tendon is double, which sometimes 

 occurs with marsupials. These investigations, which were ex- 

 plained in much technical detail, tend to prove that all the 

 muscles possessed by man can be traced backward in the lower 

 forms of animals, through the apes to the lemuroids. 



Prof. Barnard gave a detailed account of his observations on 

 the Protozoa, made in the anatomical laboratory of Cornell Uni- 

 versity, Ithaca, N. Y., where the specimens described were also 

 seen by Prof. Wilder and others than the investigator himself. 



Prof. George F. Barker, of Philadelphia, read a paper 

 On the Cause of the Relative Intensity of the Broken Lines 

 of Metallic Spectra. The purpose of this paper is to give the 

 general result of a series of measurements made to ascertain, by 

 Vierordt's method, the relative intcHsity of these various lines, 

 and to compare these whh their lengths measured micrometri- 

 cally. Vierordt's method consists in measuring the intensity of 

 a coloured light by the amount of white hght necessary to extin- 

 guish it. By means of a third telescope attached to the spectro- 

 scope, a bright sht of light may be thrown upon any portion of 

 the spectrum, and by varying the distance of the source of this 

 light, until it extinguished the various spectrum lines in the order 

 of their brightness, a series of numbers was obtained which, by the 

 law of the inverse squares, gave the relative intensity of the 

 different spectrum lines. The metals experimented upon were 

 copper, gold, silver, antimony, bismuth, and magnesium. The 

 general result is, that in no case does the length oi the spectrum 

 line follow the law of brightness. Hence some other hypothesis 

 must be suggested to account for the phenomena. The author 

 suggested one which seemed to him to be at least possible, and 

 to be sustained by the prevalent views on molecular and atomic 

 physics. The constitution of a gas is simple ; the molecules com- 

 posing it move in straight lines, and encounter each other and the 

 walls of the containing vessel in so complex a way that Prof. Max- 

 well doubts if mathematics can follow their paths. The oscillations 

 of the atoms within the molecule, arc, however, less complex ; 

 they either are simple harmonic motions themselves, or they may 

 be resolved into such. It is these harmonic vibrations which, 

 communicated to the ether, cause the spectrum lines ; the 

 number of the different forms of oscillation constituting the 

 number of lines in the spectrum, the period of any one oscilla- 

 tion determining the wave length of the corresponding line, and 

 the amplitude fixing the brilliancy of that line. These things 

 being granted, we have only to suppose what is perfectly con- 

 ceivable, that the amplitude of the vibration, the only point we 

 are now concerned with, varies with the temperature differently 

 for each of the different kinds of vibration in the molecule, or, 

 what is the same thing, with the wave length. If, for example, 

 the peculiar harmonic vibration of the atoms of a copper mole- 

 cule which gave the longest line in the green, diminished the 

 amplitude of its oscillation less rapidly than the one in the blue, 

 then this is a sufficient reason why it should be the longest. 

 We may, therefore, by inspection of a broken spectrum, conclude 

 at once on the rapidity with which the amplitude of the different 



harmonic vibrations of the atoms within the molecule decreases 

 with decreasing temperatures, this being simply in the order in 

 which the lines are arranged as to their length. This is offered 

 as a working hypothesis to be proved or disproved by special 

 investigation. From the facts already known it may be regarded 

 as antecedently probable. It seems to be a step taken into the 

 great field lying between chemistry and physics, at present a 

 great and unexplored gulf. Work done here cannot be thrown 

 away even if done to test an untenable hypothesis. It must bear 

 fruit, though it may be very different in kind from that antici- 

 pated. 



REPORT ON THE PROGRESS AND CONDI- 

 TION OF THE ROYAL GARDENS AT KEW 

 DURING THE YEAR 1874 



■pROM Dr. Hooker's recently issued report on the pro- 

 •^ gress and condition of the Royal Gardens, Kew, for 

 1874, we learn that a series of lectures, or, as they are 

 called in the report, "practical lessons," have been given 

 to the gardeners during the evenings, after working hours. 

 These "lessons" embrace the elements of structural, syste- 

 matic, and physiological botany ; of chemistry, physical 

 geography, and meteorology, in their application to horti- 

 culture ; of economic botany, forestry, &c. They are given, 

 some in the young men's Library, others in the Garden or 

 Museum. Notes of these lessons have to be taken by those 

 attending them, which, after being fairly written out in note- 

 books, are examined periodically by the teacher and corrected, 

 or more explicit instruction given if necessary. The attendance 

 at these lessons is voluntary, but the fact of " good attendance " 

 is recorded in every gardener's certificate of conduct and pro- 

 ficiency on his leaving the service of the establishment. 



These lessons have been instituted with the viiew of the better 

 education of the gardeners in subjects bearing upon their profes- 

 sion, so as to qualify them for " Government and other situations 

 in the Colonies and India, where a scientific knowledge of 

 gardening, arboriculture, &c-, is required." Most ot the 

 colonial gardens and Government plantations are at the present 

 time under the superintendence ot able men, who received at 

 some time or another instruction at Kew, 



The liability of Coffca arabica to the attack of both insects and 

 fungi have been abundantly proved of late by the visitation of 

 the so-called blights in Dominica, Southern India, and more 

 recently in Ceylon, In consequence of this a good deal of 

 interest is attached to the prosperity of the Liberian Coffee, 

 which has been distributed from Kew. On this subject Dr. 

 Hooker says : " A large stock of true Liberian Coffee has been 

 obtained through the kind efforts of Messrs. Irvine and Wood- 

 ward, of Liverpool. This is a larger and perhaps differen t variety 

 from that received from Cape Coast. . . . Large quantities of both 

 have been sent to the coffee-growing British possessions, and 

 have arrived in excellent condition. Dr. Thwaites states that 

 the Cape Coast Coffee, the safe arrival of which in Ceylon I 

 mentioned in the report of last year, is, notwithstanding that it 

 was immediately attacked by the leaf disease, doing well. He 

 also remarks that 'the Cape Coast and Liberian Coffees, although 

 they would seem to differ much as regards size of their respective 

 seeds, yet in the matter of foliage there is great resemblance 

 between them. In this latter respect they differ considerably 

 from the ordinary coffee plant of Ceylon, their leaves being a 

 good deal larger, more firm in texture, and tapering more gra- 

 dually to the base.'" 



The increased cultivation of coffee, and the introduction of 

 varieties better suited to resist the attacks of disease, has, it 

 appears, attracted the attention not only of the British Govern- 

 ment, but also of the Colonial Governments, so that a good deal 

 of correspondence has arisen with Kew on the subject. Dr. 

 Hooker says : " My attention has in consequence been directed 

 (i) to obtaining accurate reports as to the nature of the disease, 

 of which several are confounded under one common epithet ; 

 (2) to recommending measures for the cultivation of coffee in 

 colonies once famous for its production where it has been almost 

 abandoned, as well as in others where the cultivation has been 

 scarcely attempted ; and (3) to the cultivation of new and im- 

 proved varieties." 



The Blue Gum Tree (Eucalyptus globulus), which has now 

 become so popular that plants some twelve or fourteen feet high 

 may be seen growing in the open air in some of our London 

 parks, is recommended for planting by Dr. Hooker, simply on 



