Ateg. 15, 1872J 



NATURE 



303 



This has ahnost the appearance of a paradox, in view of 

 the admitted fact of the extreme variability and instal^ility 

 of these lower forms ; yet it has been generally accepted 

 as a sound inference from the law of natural selection, 

 and has greatly increased the difficulty that has been felt 

 as to the enormous time recjuired for the development of 

 all forms of life from the supposed primordial germs. But 

 if the facts of Archebiosis and Heterogenesis are true, 

 and all the lower forms of life are continually being 

 produced </<■ ito~L'L\ under the influence of unknown laws 

 of development, then we may fairly conclude that, when 

 once the earth had arrived at conditions favourable to the 

 jiroduction of living organic matter, the process of de- 

 velopment would be rapid, and an immense variety of 

 low forms of animals and vegetables would soon people 

 it. It is a fair inference, too, that if such complex or- 

 j;anisms as Ciliated Infusoria, Rotifers, Nematoids, and 

 even simple Acari, can be developed independently of 

 the slowly modifying influence of natural selection, the 

 same laws of development will continue to act a sub- 

 ordinate part much higher in the scale, and, by assisting 

 natural selection in its work, may have enabled a much 

 more rapid progress to be made. 



It is very strongly argued by Dr. Bastian that the con- 

 ception of an origin of living organisms at a single remote 

 epoch in past time, and the lineal descent of all existing 

 organisms from those primal forms, is one quite opposed 

 ta the uniformitarian and the evolutional philosophy, and 

 in the highest degree difficult to accept. It is almost 

 inconceivable that Bacteria, Moulds, Monads, Amrcba', 

 and a thousand other minute and simple organisms, 

 should still exist so universally over the earth, and 

 under such an infinite variety of simple forms, if 

 all were descended from ancestors which could hardly 

 have been more simple in the almost infinitely remote 

 past, and which throughout all that time had been 

 subject to those same causes of change and advance in 

 complexity of organisation which have resulted in the 

 varied forms of all the higher animals. Whatever laws 

 and conditions led to the production of the earliest 

 organisms, they are hardly likely to have been of so excep- 

 tional a nature as never to have occurred since. It does 

 not seem probable that the very existence of life upon the 

 earth depended on so rare and improbable a set of con- 

 ditions that, having once occurred, they should never occur 

 again in the whole period between some remote pre- 

 Laurentian epoch and the present day. If, therefore, there 

 is good evidence of the continued dc novo production of 

 lower forms of life, and of the direct transformation of 

 these into various higher and more complex organisms, 

 such a view will have many a priori considerations in its 

 favour, and will tend to bring the whole series of life- 

 phenomena into greater harmony with those of inorganic 

 nature, without in any way diminishing the mysterious 

 grandeur that surrounds them. 



But if these views should be established, we shall have 

 to form an entirely new conception of the genealogical 

 history of the various existing organisms. We shall no 

 longer have one " tree of life," but a vast number of 

 such trees, all having their roots in a similar substratum 

 of the lowest organisms, evolved at various periods of the 

 earth's history, but differing greatly in their subsequent 

 development. It is probable that by far the greater num- 

 ber of these " trees of life " have become extinct at various 

 periods of their growth, and that all existing living things 

 belong to portions of but a few " trees," some of 

 which may be comparatively recent, while others may 

 have their roots far back in the past, anterior to the earliest 

 epochs of which geology affords us a record. But not- 

 withstanding this diversity and separateness of origin, 

 through the whole life-history of our globe the progress of 

 organisation seems to have been essentially similar ; which 

 is readily explicable on the ground that living things, both 

 as regards their origin and subsequent differentiation or 



development, are the immediate products of natural laws 

 or material properties, which arc probably the same now 

 as they have ever been. Similar types of form may, 

 therefore, again and again have arisen ; and Dr. Bastian 

 remarks, that even " the vertebrate grade of organisation 

 may have been attained by ultimate branches of different 

 trees of life." It remains to be seen how far this concep- 

 tion will throw light on obscure and difficult questions of 

 biological classification, and on those facts of geological 

 succession which are most difficult to reconcile with the 

 usual view of all organisms whatever having originated 

 from a single almost infinitely remote source. 



It will now be seen, even from the very imperfect 

 sketch of its subject-ma'ter, how many questions of the 

 highest scientific importance rise out of the facts adduced 

 in Dr. Bastian's work. It is not too much to say that, if 

 its main conclusions are established, it will create a 

 revolution in organic philosophy of equal importance 

 with that which was effected by Mr. Darwin, whose 

 observations and mot important theories will, however, 

 remain unaffected by it. That gentleman has himself re- 

 marked that " analogy is a deceitful guide," and it is only 

 by analogy that he extends the laws he has estabhshed 

 for the higher animals and plants to those lower forms 

 with which Dr. Bastian de ds ; and the establishment of 

 facts proving that they co ne under a different category 

 will even relieve the theory of natural selection from some 

 of its greatest difficulties, and neutralise some of the most 

 serious objections that have been brought against it. The 

 whole question, however, is primarily one of facts, and, 

 however it may be ultimately decided, every lover of 

 science must admire the courage and energy with which 

 Dr. Bastian has taken up an unpopular subject, the skill 

 and patience with which he has experimented, the labour 

 which he has bestowed in collecting the records of widely 

 scattered and almost forgotten observations, and the 

 logical force as well as the philosophical spirit with which 

 he has worked out his conclusions. It is a book that 

 cannot be ignored, and must inevitably lead to renewed 

 discussions and repeated observations, and through these 

 to the establishment of truth. 



Alfred R. Wallace 



NOTES 



The Lords of the Committee of Council on Education having 

 decided to transfer the instruction in Physics, Chemistry, and 

 Natural History from the Royal School of Mines in Jermyn 

 Street, and the College of Chemistry in Oxford Street, to the 

 new buildings in Exhibition Road, .South Kensington, notice has 

 been given that in future the following courses of lectures and 

 practical laboratory instruction will be given at South Kensington 

 at the date specified : — Chemistry by Prof Frankland, D.C.L , 

 F. R S. A course of forty lectures on Inorganic Chemistry com- 

 mencing 2tst of October, 1S72. A course of thirty lectures on 

 Organic Chemistry commencing 13th of January, 1S73. Labo- 

 ratory instruction consisting of an elementary and an advanced 

 course commencing on 1st of October. Biology by Prof Huxley, 

 LL.D., F.R.S., a course of eighty lectures on Biology (or 

 Natural History, including Pahi:ontology) with laboratory in- 

 struction, commencing the 7th of October, 1872. Physics by 

 Prof. Frederick Guthrie. The course will consist of lectures, 

 with laboratory work on the subject of the lectures, divided 

 as follows : — Twelve lectures on Molecular Physics, Sound, &c., 

 commencing 24th of February, 1873 ; fifteen lectures on Heat, 

 commencing on 24th of March ; fifteen lectures on Light, com- 

 mencing on I2th of April ; twenty lectures on Electricity and 

 Magnetism, commencing on igth of May. Each course will be 

 complete in itself, and may be taken separately. 



