372 



NATURE 



[June 29, 19 16 



with his means of allaying pain and fever, of regu- 

 lating many physiological functions, of neutralising 

 bacterial poisons, and of determining the death of the 

 parasites of disease. Already the chemical manu- 

 facture of pharmacologically active substances con- 

 • stitutes one of the vital activities of modern civilisation. 

 But the application of chemical science to physiology 

 and medicine is in its earliest infancy, though it will 

 lead in time to advances as yet undreamt of. For 

 further progress we require a finer and more subtle 

 analysis of those wonderful chemical and physico- 

 chemical changes which preserve the mobile and 

 dynamic equilibrium of living matter. 



The problem of life, of living matter, forms one of 

 the great goals of chemical science, on the slow and 

 progressive solution of which depend our future exist- 

 ence and well-being. At the other end of the long 

 chain of evolution lies the problem of the birth of 

 matter. This is perhaps the other great goal of 

 chemical science. It is a very long way from the 

 shining nebula to the speck of protoplasm. There are 

 many who would dig an impassable ditch in this long 

 road. 



But however that may be, the question of the 

 synthesis and possible reconstruction of what we call 

 our material world is one of truly transcendant import- 

 ance. The discovery that the atoms of matter can, 

 and in certain instances actually do, break up into 

 other atoms and into electricity we owe to the genius 

 of French and British science, and the first recog- 

 nisable transmutation was discovered at Univer- 

 sity College, London, by Sir William Ramsay 

 and Prof. Soddy. So tremendous, however, are 

 the forces in operation during these changes 

 that hitherto it has proved impossible to con- 

 trol them irt any wise. I might perhaps mention 

 that we owe to Sir William Ramsay and to Prof. 

 Norman Collie the first determined and courageous 

 attempts »to begin this battle of the giants. We find 

 ourselves here in a new world of chemical and mole- 

 cular science. We are the spectators of forces and 

 velocities hitherto undreamt of. But the progress of 

 electrical science, which has ever been the fairy god- 

 mother of chemistry, gives us reason to be of good 

 courage. 



Already we know that electricity, which is but a finer 

 form of matter, is a component of the atom. We know 

 from the researches of von Laue and of Prof. Bragg 

 and his son that the excessively short electric waves sent 

 out by certain forms of electrical discharge, the so- 

 called X- or Rontgen-rays, can penetrate and analyse 

 the exceedingly fine-grained atomic structure of a 

 ci-ystal. Is it too much to hope that still shorter and 

 denser electric waves, sent out by the most powerful 

 sources, may be able some day to penetrate the very 

 core and nucleus of the atom and disturb the potent 

 equilibrium that reigns therein? 



The researches of astronomers, chemists, and 

 physicists have shown that in the gaseous nebulae and 

 the early stars matter exists in forms as yet unknown 

 to us on our planet, and that as the progress of stellar 

 evolution proceeds we gradually arrive at stars akin 

 in nature and composition to our sun and our own 

 world. Is it too much to hope that we may so suc- 

 ceed in employing electricity and electrical energy as 

 synthetic reagents that we shall eventually, and 

 indeed perhaps at no distant date, arrive at the pro- 

 duction of these simple and primary forms of nebu- 

 lous matter? Whether these problems will admit of 

 solution in the near or the distant future, or whether, 

 indeed, some of those which I have mentioned will 

 ultimately defy all our efforts, it is here that I would 

 ask you to seek the profound rdle which chemical 

 science is destined to play in civilisation. 



NO. 2435, VOL. 97] 



I 



E VOL UTION AND S YMMETR } .1 

 N the animal kingdom two dominant types of body 

 symmet/y are to be found. In animals that are 

 sedentary or floating in habit the symmetry is fre- 

 quently radial, but in animals that are free and move 

 rapidly by their own muscular activity the symmetry is 

 bilateral. In those classes of animals now sedentary 

 in habit, which by their developmental history show 

 a descent from a previously free and bilaterally sym- 

 metrical ancestry, a secondary -radial symmetry is 

 usually found either in the form of the body or in the 

 arrangement of the organs for the capture of food. 

 Similarly in the Echinodermata some examples are 

 found, particularly in the class Holothuroidea, of 

 animals descended from a sedentary and radially sym- 

 metrical ancestry assuming with their freedom and 

 increased muscular activity a secondary bilateral sym- 

 metry. 



In the groups of animals that are radially sym- 

 metrical, whether sedentary or floating in habit, there 

 is usually a far greater range of variability than in those 

 that are bilaterally symmetrical, and in the endeavour 

 to classify them into genera and species on the Linnean 

 system the zoologist finds so many cases of overlapping 

 and fusion that some doubt arises as to the existence 

 in Nature of discontinuous specific groups. 



In the order of the sea-pens there is a complete 

 series of forms connecting the radially symmetrical 

 colonies of the genera Veretillum and Cavernularia 

 with the bilaterally symmetrical genera Pennatula and 

 Pteroeides. In this series the difference between the 

 range of variation in the radially symmetrical genera 

 and that in the bilaterally symmetrical genera is very 

 pronounced. 



In such characters as the size of the zooids, the size 

 and shape of the spicules, and the length of the axis, 

 remarkable variations are found in the radially sym- 

 metrical genera. In the bilaterally symmetrical genera 

 these characters are far more definitely fixed, and can 

 usually be relied upon for determination of species. 



Having examined a large number of specimens of 

 the Pennatulacea collected by the Siboga expedition 

 and in other collections in this country and abroad, 

 the author believes that in some of the radially sym- 

 metrical genera there is no such discontinuity of stinjc- 

 ture as would justify their division into specific 

 groups. In the bilaterally symmetrical genera, on the 

 other hand, the existence of definite specific groups is 

 certain. If this view is justified, the conclusion would 

 be reached that the evolution of those discontinuous 

 groups of specimens which are commonly recognised as 

 species is correlated with the change from a radially 

 symmetrical to a bilateral symmetry of the body. 



The evidence at present at our disposal points very 

 definitely to the conclusion that the radially sym- 

 metrical sea-pens are more primitive than the bilater- 

 ally symmetrical sea-pens, and evidence is produced 

 which suggests that the former are derived from an 

 Alcyonacean ancestry which assumed a floating or 

 drifting habit. 



UNIVERSITY AAW EDUCATIONAL 

 INTELLIGENCE. 



Glasgow. — The degrees conferred on Commemora- 

 tion Day, June 26, included the following : — Doctor 

 of Laws (honoris causd). Dr. J. Ferguson, emeritus 

 professor of chemistry; Doctor of Letters, W. H. 

 Dunn, thesis, "The Development of English Bio- 

 graphy "; Doctor of Science, Alex. Scott, thesis, 'Con- 



1 Summary of ihe Croonian Lecture on " Evolution and Symmetry in the 

 Order of the Sea-pens," delivered before the Royal Societv on June 2a by 

 ■Prof. S.J. Hickson, F.R.S. 



