286 



NATURE 



[November ii, 19 15 



ing from the other in sharply-defined characters, 

 which, being products of the germ-plasm, are trans- 

 missible, though they may be eliminated by selection. 

 He contrasts this view, which is not according to the 

 Darwinian tradition as commonly accepted, with his 

 own — which is entirely "Darwinian " — based on osteo- 

 logical characters according to which the evolution of 

 species is quite otherwise, demonstrating a condition 

 of continuous development to be traced by means of, 

 say, a horn or the cusp of a tooth ; or, in other words, 

 on "characters which happen to be so conspicuous as 

 to attract the eye of the zoologist." 



Having disposed of the Darwinian "tradition," he 

 proceeds to point out a more excellent way of inter- 

 preting the mazes of evolution, and this by means of 

 a "newly-discovered law of multiple-evolution" derived 

 from the discoveries of palaeontology, which "proves" 

 that "every organism is made up of an almost infinite 

 number of characters, each of which is in a continuous 

 state of movement, either originative, progressive, or 

 retrogressive." But this idea of "multiple-character 

 evolution " cannot fairly be said to be new. Further, if 

 Prof. Osborn has independently arrived at this con- 

 ception of evolution, he has done so through his own 

 wide knowledge of living animals, and not entirely, as 

 he seems to believe, through his brilliant discoveries 

 in palaeontology. Palaeontology, in short, cannot be 

 said to "prove" that every organism is made up of 

 an infinite number of characters . . ." for palaeonto- 

 logy can "prove" no more than can be attested by 

 such skeletal and dermal structures as are capable of 

 fossilisation. The characters furnished by musculature, 

 viscera, " behaviour," and the "emotions," for example, 

 are all factors of evolution which can only be im- 

 perfectly inferred, not demonstrated, by the palaeonto- 

 logist. 



In stating that Prof. Osborn could find "no evidence 

 whatever in support of the theory that species may 

 arise from fortuitous, saltatory characters," the re- 

 viewer felt that he was accurately interpreting Prof. 

 Osborn's assurance that he did not "know of a single 

 instance where the field observer in mammalogy or 

 palaeontology has recorded a new saltatorial character 

 which is known to be of any significance to the race." 

 Prof. Osborn's reference to teratological cases does 

 not seem to help him. 



The reviewer frankly admits that he was wrong in 

 suggesting that Prof. Osborn was to be regarded as 

 in sympathy with the theory of evolution by loss of 

 characters. The Reviewer. 



Simple Device for Controlling the Movements of 

 Paramoecia. 



Everyone who is concerned in the teaching of 

 elementary zoology knows the great difficulty of so 

 controlling the movements of Paramcecium that 

 students can distinguish the essential features of its 

 structure. Of all the methods adopted for this pur- 

 pose of which I have hitherto heard, none has ever 

 given me such successful results as one which I tried 

 recently in this department as an experiment, and the 

 advantages of which combine simplicity with very 

 great control over the animals. 



A small quantity of ordinary gum is painted on a 

 glass slide, and allowed to become nearly dry; a drop 

 of water containing the Paramoecia is then placed on 

 the gum and covered in the ordinary way with a 

 cover-glass. At first the gum will scarcely interfere 

 with the movements of the animals at all, but within 

 a few minutes, as the gum diff'uses through the water, 

 they will be seen to move more and more slowlv, and 

 ultimately they will be unable to move at all. Finally, 

 the irritation caused by the gum will result in the 

 discharge of the trichocysts. 



NO. 2402, VOL. 96] 



This method of using the gum enables the student 

 to observe the Paramoecia at first in an almost normal 

 condition, and afterwards to make a careful and de- 

 tailed examination of them at his leisure. The normal 

 shape and appearance are retained for a long time, 

 even when the animal has become stationary, save that 

 the gullet tends gradually to disappear, possibly 

 through clogging with the gum. 



R. W. Harold Row. 



Zoological Department, King's College 



(University of London), November 8. 



MONUMENTS AND LIGHTNING. 



THE liability of monuments to be struck by 

 lightning is the subject of a recent memoir 

 in the Atti delta Pontificia Accademia dei Nuovi 

 Lincei by Prof. Ignazio Galli. The occasion of 

 this note was the destruction at Santamaria di 

 Capua Vetere, in the province of Caserta, in Octo- 

 ber, 1914, of a fine monument erected in 1895 in 

 memory of the battle fought near to Volturno in 

 i860. This monument of travertine marble, about 

 95 feet high, consisted of a stately column on a 

 substantial pedestal, surmounted by a colossal 

 bronze statue of Victory about 10 feet high, 

 weighing 1500 pounds. This statue w.as fixed in 

 the summit of the column by an iron rod which 

 penetrated about half-way down the column. The 

 monument stood in the quadrangle of the com- 

 munal building, far from any high trees. During 

 a violent thunderstorm about 2 a.m. a lightning 

 stroke threw down the great bronze statue, and 

 destroyed the upper half of the column. It is 

 thought that the destruction might have been 

 averted had an efficient metallic conductor con- 

 nected, the bottom of the iron rod to a damp 

 stratum of soil. It is evident that an insulating 

 mass of marble, many feet high, between a metal 

 object and the earth affords no protection what- 

 ever against a severe thunder-stroke. 



Prof. Galli takes occasion to refer to similar 

 catastrophes which befell a column at Constan- 

 tinople in the year 548, and another dedicated to 

 Constantine the Great in the same city in the year 

 iioi. In Rome in the fourteenth century the 

 column of Marcus Aurelius Antoninus was badly 

 damaged at the top ; and in the same century the 

 statue of Trajan on the summit of the celebrated 

 column of Trajan was likewise destroyed. Tacitus 

 records how in the year 61 a.d. the Baths of Nero, 

 erected scarcely one year before, were destroyed by 

 lightning. More recent times have witnessed the 

 destruction of the tower of the Castello of Milan 

 (1521), that of Ivrea (1676), of San Nazaro at 

 Brescia (1769), and of the fortress of the Lido at 

 Venice (1808). In 1572 the flagstaff of the Castle 

 of St. Angelo in Rome was destroyed, with the 

 bronze statue of the Archangel Michael. Between 

 the years 1606 and 1809 the basilica of St. Peter's 

 was struck, generally on the cross or the golden 

 ball, at least twenty-two times. On the last occa- 

 sion (1809) the Pope, Pius VII., had already 

 begun preparations for fixing lightning conduc- 

 tors. For more than a whole century these 

 conductors have effectually preserved the struc- 

 ture from damage. 



