September 24, 1914] 



NATURE 



107 



of germ-cells in the animal body, to which Weismann 

 attached so much importance. The fact is that the 

 constitution of the higher plants and of the higher 

 animals is in this, as in many other points, radically 

 different, and arguments from one to the other 

 are dangerous in the extreme. Tho^e who interest 

 themselves in evolutionary questions do not, I think, 

 sufficiently realise that the utmost that can be claimed 

 is analogy between the higher terms of the two 

 kingdoms. Their phyletic separation certainly dates 

 from a period prior to that of which we have any 

 knowledge from the fossil record. Let us give full 

 weight to this fact, as important as it is indisputable. 

 The early definition of germ-cells in the animal body 

 will then count for nothing in the evolutionary' problem 

 of plants. Moreover, we shall 

 realise that the plant, with 

 its late segregation of germ- 

 cells, will present the better 

 field for the inquiry whether, 

 and how far, the environment 

 may influence or induce 

 divergences from type. From 

 this point of view the wide- 

 spread opinion among botan- 

 ists that the environment in 

 some sense determines the 

 origin and nature of diverg- 

 ences from type in plants 

 should command a special 

 interest and attention. 



I must now draw to a close. 

 1 have passed in review some 

 of your more notable plants, 

 and pointed out how the 

 Australasian flora, whether 

 living or fossil, includes 

 in unusual richness those 

 evidences upon which the 

 fabric of evolutionary- his- 

 tory is being based. I 

 have indicated how this 

 history in certain groups 

 is showing ever more and 

 more evidence of parallel 

 development, and that such 

 development, or convergence, 

 presses upon us the inquir}' 

 into the methods of evolu- 

 tionary- progress. The illus- 

 trations I have brought for- 

 ward in this address clearly 

 show how important is th*^ 

 positive knowledge derived 

 from the fossils in checking 

 or confirming our decisions. 

 Palaeophytology- is to be 

 prized not as a separate 

 enthusiastic view restricted 

 recent writer 

 treat it so 



THE WIDMAXSrATTEN STRICT IRE IM 

 VARIOUS ALLOYS AND METALS.^ 



T^HE surface of meteoric iron after p>olishing and 

 ^ etching in the way usually adopted, prior to 

 examination under the microscope, shows character- 

 istic figures which are for the most part triangles or 

 parallelograms. These figures were observed for the 

 first time in 1808 by M. Alois de Widmanstatten, the 

 director of the Imperial Porcelain Works at Vienna 

 on the- Ilraschina meteorite, and although Widman- 

 statten himself had published nothing regarding his 

 discoveries, a knowledge of them spread very quickly, 

 and what he had seen were soon universally known 

 under the name of "Widmanstatten figures." It was 







mm 





Fig. 



Widmanstatten Struciure in Carbon Steel (Carbon 0-55 per cent.). 

 AUuy No. S. Ma^iiitied 8 aiamcter^. 



science, as, with an 



between blinkers, a 



has endeavoured to enforce. To 



would be to degrade it into a 



mere side alley of study, instead of holding it to be 

 the most positive line that we p)OSsess in the broad 

 avenue of botanical phylesis. An appreciation of such 

 direct historical evidence is no new idea. Something 

 of the same sort was felt by Shakespeare three cen- 

 turies ago, and it remains the same to-day. Nay, 

 more : it may lead us even to forecast future possibili- 

 ties. In following our evolutionary quest in this spirit 

 we shall find that we are indeed — 



" Figurine rhe nature <f the times dec»a*ed 

 The which observed, a man may prophesy 

 With a near aim, of the main chance of things 

 As yet not come to life." 



._ NO. 2343, 



(King Henry IV., 

 VOL. 94] 



Part II, Act iii., Seece i.) 



then generally considered that these figures were char- 

 acteristic of meteoric iron and that they were not 

 found in terrestrial iron. Guillet-Laumont - in 1813 

 already saw an analogA' between the two varieties of 

 iron ; but the majority of investigators for a long 

 time were of a different opinion, and the views of 

 Guillet-Laumont were forgotten. 



The interest in meteorites shown by Dr. Sorby, the 

 founder of the science of metallography, and especially 

 the brilliant researches of Osmond, led anew to atten- 

 tion being directed to the figures of Widmanstatten. 

 Thus it was that in 1900 M. Osmond announced the 

 discover^' in the head of a steel ingot of equilateral 

 triangles which recalled, he said, "the figures of Wid- 



1 Paper pre-enied to ibe Institute of MeiaU for the St-pember meeting 

 by Cai t. N. T. B^laiew (Micbaei Artill.-ry Academy, Peirograd). Trans- 

 lated fmm the Fre> ch of the original MS. of Capt. Bclaicw, and, in 

 consequence of 'he European War, not since rerised by him. 



S Cohen, Mete<nHtenkundt, 1894, vol. L, p 41. 



