Sept. 7, 1876J 



NATURE 



393 



employment for his pen in proposing such alterations or addi- 

 tions to these rules as would remedy the " grievance " (as I term 

 it) or the " evil practice " (as he prefers to call it), and in that I 

 can assure him he would meet with hearty co-operation from all 

 English naturalists, and from none more heartily than from the 

 undersigned. R. Bowdler Sharpe 



The Origin of Variations 



There is a slight difference between all three of the answers to 

 Mr. Murphy's queries on Protective Mimicry (vol. xiv. pp. 309, 

 329) ; but, I think, the authors of those replies are unanimously 

 over-hasty to call in the aid of protective selection. I cannot but 

 think that the perpetuation of nascent variations may more safely 

 be attributed to causes identical with those in which the varia- 

 tions originate. If this be so, though the origin of variation 

 is necessarily beyond the scope of any selection-theory, these 

 causes continuing to act on the varying organism become of vast 

 importance to the evolutionist. Too much importance cannot, 

 I think, be given in this connection, to the principle of economy 

 of nutrition, or balancement of growth, formulated by Aristotle, 

 in the words ''^ afxa Se t^i/ axiT^^v yjrepox')'' *t's iroWous riirovs 

 dSvyaru Siayf/xeiv -q ipvcis," and by Goethe, in the expression 

 " Nature, in order to spend on one side, is forced to economise 

 on the other." I gave one example of this law in a previous 

 letter (Nature, vol. xiii. p. 107) in speaking of the indirect 

 uses of the waste, or secondary products of metastasis in plants ; 

 but as the subject is admirably sketched in Mr. Lowne's sugges- 

 tive essay on "The Philosophy of Evolution," a work too little 

 known or appreciated, I will give here an outline of the argu- 

 ment. Food may be divided into three parts — for nutrition, for 

 the production of energy and waste, or excretion. In many 

 lower organisms the excreted material forms a simple shell ; in 

 plants manna, nectar, and resins belong to this group. The 

 chief form of energy in the organic kingdom is that resulting 

 from the oxidation of carbon, chiefly characteristic of animals, 

 while plants secrete the energy-producing material. In higher 

 organisms it is physiologically advantageous that the parts of an 

 organism should diffdr in the kind of nourishment they require 

 and thus act, as Sir James Paget has shown, as excretory organs 

 to one another. Thus all animals which feed on large quantities 

 of comparatively slightly nutritious matter have a complicated di- 

 gestive apparatus, aad a strong tendency to the production of large 

 skeletons or cutaneous organs, which relieve the special excretory 

 organs. The stag applies a large portion of the calcareous salts 

 derived from the herbage to the production of horns in the male 

 and the bones of the young in the female. The thoracic appen- 

 dages of the lamellicorns and the beaks of the toucan and horn- 

 bill are given as further examples, and " the dermal appendages 

 of reptiles and the feathers of birds, rich in pigment and nitrogen 

 are probably entirely excrementitious to the other tissues." 

 Mr. Lowne makes an interesting final application of this hypo- 

 thesis to the loss of the hairy covering of the human skin, it 

 being the albuminous tissue most easily dispensed with to nourish 

 the highly developed nervous system. " Phosphorus was like- 

 wise required in large quantities and the osseous system became 

 reduced in size." The composition of the nutrient fluid of the 

 organism remaining constant, the excreted matter will be so 

 also, and thus, for example, a rudimentary horn or a pigment 

 may be produced by a change of food and preserved, while the 

 food remains the same, by a physiological selection, as prevent- 

 ing the overtaxing of the kidneys, before sexual selection or pro- 

 tective selection come into play. I have an instance in point 

 before me. Two plants of variegated kale under the influence of 

 the late drought have produced axial structures from the midribs 

 and veins of all their leaves, and I have no doubt that were 

 their seedlings grown under similar nutritive conditions, a race 

 of plants thus substituting fibro-vascular tissue for the usually 

 abnormal development of parenchyma in the kale would be pro- 

 duced. G. S. BOULGER 



Agricultural College, Cirencester, Aug. 25 



THE BRITISH ASSOCIATION 



THE forty- sixth Annual Session of the British Asso- 

 ciation was formally opened last night by the 

 address of the president, Prof. Andrews, of Belfast. 

 From the reports of the preparations we have already 

 given, it will have been seen that unusual efforts have 

 been made to render this Glasgow meeting a success, and 



so far as can be judged at present this 'end has been 

 gained. This is the third time the Association has met 

 in Glasgow. The first occasion was in 1840, when the 

 Marquis of Breadalbane was president, and the last time 

 in 1855, when a similar honour was conferred on the Duke 

 of Argyll. This is the eighth time the Association has 

 held its meeting in Scotland, Edinburgh, having been the 

 first northern town visited, so far back as 1834, four years 

 after the foundation of the Association ; the Scottish 

 capital was again visited in 1850 and 1871 ; Aberdeen in 

 1859, when Prince Albert was president ; and Dundee 

 in 1867. 



The arrangements for the evening lectures, about which 

 there was at one time some difficulty, have been happily 

 completed. The first lecture will be delivered on Friday 

 in the Kibble Palace, by Prof. Tait ; the second, for 

 working-men, in the City Hall, on Saturday evening, 

 probably by Commander Cameron, R.N. ; and the third 

 on Monday, Sept. 11, in the Kibble Palace, by Prof. Sir 

 C. Wyville Thomson. 



Among the foreign visitors who are expected at the 

 Glasgow meeting, are : — Dr. Janssen, Prof. Negri, of 

 Florence, Prof. Braune, Leipsic, Dr. Edward Grubi, 

 Breslau, Prof. Cohn, Breslau, Prof. Stoletow, Baron von 

 Wrangell, St. Petersburg, and Prof. Cerati, Rome. 



The specially prepared Guide-book to Glasgow is in 

 three volumes, some of the former guides of this descrip- 

 tion being considered too bulky. The volumes will be 

 full of interesting information regarding such subjects as 

 the geology of the Valley of the Clyde, fossils found in the 

 West of Scotland ; the archaeology, zoology, and botany 

 of the district ; the rise and progress of the iron manu- 

 facture in Scotland, chemical industries, the engineering 

 and ship-building industries of the Clyde, and the textile 

 industries of Glasgow and neighbourhood. Mr. Graham, 

 the Hon. Secretary of the Association, has prepared an 

 excellent sketch map of the country surrounding Glas- 

 gow, with its general geological features, which has been 

 lithographed, and will be inserted in one of the volumes. 

 Each member of the Association will be presented with a 

 copy of the handbook. 



Inaugural Address of Thomas Andrews, M.D., LL.D., 

 F.R.S., Hon.F.R.S.E., M.R.I.A., &c., Preside nt. 



Six and thirty years have passed over since the British .Asso- 

 ciation for the Advancement of Science held it> tenth meeting in 

 this ancient city, and twenty-one years have elapsed since it last 

 assembled here. The representatives of two great Scottish 

 families presided on these occasions ; and those who had the 

 advantage of hearing the address of the Duke of Argyll in 1855 

 will recall the gratification they enjoyed while listening to the 

 thoughtiul sentiments which reflected a mind of rare cultivation 

 and varied acquirements. On the present occasion I have under- 

 taken, not without anxiety, the duty of filling an office at first 

 accepted by one whom Scotland and the Association would alike 

 have rejoiced to see in this Chair, not only as a tribute to his 

 own scientific services, but also as recognising in him the worthy 

 representative of that long line of able men who have upheld the 

 pre-eminent position attained by the Scottish schools of medicine 

 in the middle of the last century, when the mantle of Boerhaave 

 fell upon Monro and Cullen. 



The task of addressing this Association, always a difficult one, 

 is not rendered easier when the meeting is held in a place which 

 presents the rare combination of being at once an ancient seat of 

 learnmg and a great centre of modern industry. Time will not 

 permit me to refer to the distinguished men who in early days 

 have left here their mark behind them ; and I regret it the more, 

 as there is a growing tendency to exaggerate the value of later 

 discoveries, and to underrate the achievements of those who have 

 lived before us. Confining our attention to a period reaching 

 back to little more than a century, it appears that during that 

 time three new sciences arose, at least as far as any science can 

 be said to have a distinct origin, in this city of Glasgow — Expe- 

 rimental Chemistry, Political Economy, and Mechanical Engi- 

 neering. It is now conceded that Black laid the foundation of 

 modern chemistry ; and no one has ever disputed the claims of 

 Adam Smith and of Watt to have not only founded, but largely 



