Dec. 5, 1878] 



NATURE 



1^3 



islands of the globe, their composition, and their relations to 

 one another, and to those of previous geological epochs. He 

 then discusses the views of botanists respecting their origin and 

 distinctive characters, and availing himself of such of their 

 hypotheses as he thinks tenable, correlates these with those of 

 palxontologists, and arrives at the conclusion * ' That the northern 

 hemisphere has always played the most important part in the 

 evolution and distribution of new vegetable types, or in other 

 words, that a greater number of plants has migrated from north 

 to south than in the reversed direction, and that all the great 

 assemblages of plants which we call floras, seem to admit of 

 being traced back at some time in their history to the northern 

 hemisphere." This amount of accordance between the results 

 of naturalists working wholly independently, from entirely 

 different standpoints, and employing almost opposite methods, 

 cannot but be considered as veiy satisfactor}-. I will conclude by 

 observing that there is a certain analogy between two very salient 

 points which are well brought out by these authors respectively. 

 Count Saporta, looking to the past, makes it appear that the 

 fact of the several floras which have flovurished on the globe 

 being successively both more localised and more specialised, is in 

 harmony with the conditions to which it is assumed, our globe has 

 been successively subjected. Mr. Dyer, looking to the present, 

 makes it appear that the several floras now^existing on the globe, 

 are in point of affinity and specialisation, in harmony with the 

 conditions to which they must have been subjected during recent 

 geological time on continents and islands w ith the configuration 

 of those of our globe, 



{To he cojititmed.) 



HAECKEL ON THE LIBERTY OF SCIENCE 



AND OF TEACHING-*- 

 pROF. HAECKEL has recently published his reply to the 

 ■*■ address on " The Liberty of Science in the Modern State," 

 delivered at last year's meeting of the German Association, by 

 Prof. Yirchow. If we enter into this subject at greater length 

 than is our custom with pamphlets we do so mainly from a 

 sense of common fairness to both parties, since we reproduced 

 Prof. Virchow's address in extenso (Nature, vol. xvii. pp. 72, 

 92, and III). We shall, however, confine ourselves merely to 

 stating Prof. Haeckel's views on the subject, and leave it to our 

 readers to judge of the value of his remarks for themselves. 



In the preface to the little book before us Prof. Haeckel states 

 that the general views developed by Yirchow are in such com- 

 plete contrast to his own that no reconciliation of the two is 

 possible. Yet he refrained for a considerable time from pub- 

 lishing his reply ; and this for two reasons. On the one hand, 

 he thought he might safely leave the judgment of the strife 

 between them to the future ; first, because the evolution theory, 

 which Yirchow attacks, has, de facto, become the basis of bio- 

 logical science of the present day ; secondly, because Yirchow's 

 objections to the theory of descent have been so frequently and 

 thoroughly refuted that it seemed superfluous to refute them 

 again. On the other hand, he felt great reluctance in opposing 

 a man whom a quarter of a century ago he honoured as the 

 reformer of medical science, and whose pupU and zealous 

 admirer he was for many years. 



"The more I for years regretted Yirchow's position as the 

 enemy of our new evolution theorj', and the more I was 

 challenged to reply by his repeated attacks upon it, the less 

 inclination I felt, nevertheless, to appear publicly as the anta- 

 gonist of the highly -honoured and meritorious man. If now I 

 find myself forced to reply, I do so with the conviction that 

 longer silence would only augment the erroneous views which 



my resignation hitherto has already produced I must 



point out distinctly that it is not Yirchow but I who am the 

 person attacked, and that in my case there is no question of 

 attacking a formerly highly-honoured friend, but of defending 

 myself by necessity against his repeated and violent attacks. 

 Another reason which compels me to speak at last lies in the 

 continued fertile use made of Yirchow's speech by all clerical 

 and reactionary organs for the last nine months. . . . Already 

 Friedrich von HeUwald h^s pointed out the great danger which 

 lies in the fact that it was a Yirchow who, imder the banner of 

 political Liberalism, and WTapped in the mantle of pure science, I 

 combated the liberty of science and of its teaching." 



The author then continues to point out that the danger was ! 



' f re'e Wissenschaft und freie Lehre. Eine Entgegnung auE Rudolf 

 Virchow's Mimchener Rede fiber " die Freiheit der Wissenschaft im modemen 

 Staat. Von Ernst Haeckel. | 



never so great in Germany as at the present moment, where tht 

 political and religious life of the German nation seems to ap- 

 proach a profound reaction. The two mad attempts upon the 

 life of the honoured and aged Emperor have called forth a 

 storm of just indignation of such violence that even many 

 Liberal politicians not only press for severe measures against the 

 Utopian teachings of social democracy, but, far overshooting 

 the mark, demand that free thought and free teaching should 

 be confined within the narrowest bounds. What more welcome 

 support can the reactionary party wish for than that a Yirchow 

 should publicly demand the suppression of the liberty of 

 science? The danger appears still greater to Prof. Haeckel 

 if Yirchow's great influence as a "liberal Progressist" is taken 

 into consideration, now that the Prussian Diet will shortly open 

 its debates on the educational law. "What," Prof. Haeckel 

 asks, "may we expect of this educational law, if in the discus- 

 sions Yirchow, as one of the few authorities who wUl be con- 

 sulted, raises his voice in favour of the principles which in his 

 Munich speechhe proclaimed as the safest guarantees forthe liberty 

 of science in the modem state. Article 20 of the Prussian 

 Constitution, and § 152 of that of the German Empire say: 

 Science and its teachings are free. Yirchow's first action, accord- 

 ing to his present principles, must be a proposal to cancel this 

 paragraph. In view of the menacing danger, I cannot hesitate 

 any longer with my reply. Amicus Socrates, amicus Plato, 

 magis amica Veritas ! " The rest of the preface is concerned 

 with a refutation of the "denunciation" by which Yirchow 

 wants to make the theory of descent responsible for the horrors 

 of the Paris Commune. Haeckel thinks that by an intentional 

 coupling of Darwinism with Social democracy, Yirchow in- 

 tended to do considerable damage to the former, indeed he sees 

 in it an 'attempt to remove all " Darwinists " firom their Aca- 

 demical chairs. At the same time he points out that nine out of 

 ever)' ten zoologists and botanists now teaching at European imiver- 

 sities are Darwinists. Yirchow's attempt is therefore perfectly 

 futile, and will certainly never have any effect at Jena. " What 

 the Wartburg was for Martin Luther, what Weimar was for the 

 greatest heroes of German literature, what Jena has been during 

 Qiree centuries for a large number of scientific men, that will 

 Jena continue to be for the evolution-theory of the present day, 

 as well as for all other scientific theories which develop freely, 

 viz., a firm stronghold for free thought, free research, and firee 

 teaching." 



We now come to the first chapter, which is headed " Evo- 

 lution and Creation." The author remarks at the b^inning that 

 nothing has so greatly facilitated the progress of the evolution 

 theory, as the fact that its principal problem, the question of the 

 origin of species, was placed before the alternative : Either 

 organisms have been dcviloped naturally, in which case they 

 must descend from the simplest and common ancestral forms — 

 or this is not the case, and the different species of organisms have 

 originated independently of one another, in which case they can 

 only have been created in a supernatural way, i.e., by a miracle. 

 Natural development or supernatural creation of species — ^the 

 choice must here be made, since a third way does not exist. 

 Since Yirchow and many other antagonists of the evolution 

 theory constantly mix this up with the theory of descent, and 

 this again with the theory of natural selection or Darwinism, 

 Prof. Haeckel does not think it superfluous to give a concise 

 definition of each of the three great theories at starting. He 

 then states his definitions as follows: — "The relation of 

 these theories according to the present state of science is there- 

 fore simply the following : — I. Monism, the universal theory of 

 evolution, or the monistic pro-genesis theory, is the only scien- 

 tific theory, which rationally explains the universe and satisfies 

 the desire for causality in the human mind, since it brings all 

 natural phenomena into a mechanical causal connection as parts 

 of a great and uniform [einheitlich) process of development ; 

 II. Transformism, or the theory of descent, is an essential and 

 indispensable part of the monistic evolution theory, because it 

 is the only scientific theory which explains the origin of organic 

 species in a rational manner, viz., by transformation, and reduces 

 this transformation to mechanical causes; III. The theory of 

 selection, or Darwinism, is up to the present the most important 

 one amongst the different theories, which try to explain the trans- 

 formation of species by mechanical causes ; but it is by no means 

 the only one. Even if we suppose that most species have originated 

 through natural selection, yet w-e know, on the other hand, that 

 many forms called species are merely hybrids from two different 

 species and are propagated as such; at the same time we 



