August io, 191 1] 



NATURE 



183 



give a summary of the results achieved in some par- 

 ticular group. 



The day's work is arranged and carried out in such 

 a way as to give the student opportunity of observing, 

 forming opinions of his own, and gaining confidence 

 in his own judgment. There also the student is 

 taught to get at the root of things, and, without 

 knowing it, gradually copies the example and is 

 imbued with the earnestness of the director. 



The general routine differs very little from that 

 followed in most German universities, and yet year 

 after year every Arbeitsplatz in the institute is occu- 

 oied, and that by a very cosmopolitan group of zoolo- 

 gists and of zoologists in the making. 



Why is it that students from all quarters flock 

 there? It is certainly not due to the equipment, for 

 many of the newer zoological institutes in Germany 

 are more lavishly equipped ; nor is it due to the fact 

 that the institute is situated in a very pleasant town. 

 On the contrary, it is due to the reputation, but still 

 more to the personality of the director. 



Prof. Weismann's research has covered a wide field, 

 and the resulting articles are all marked by a thorough- 

 ness and a mastery of detail which shows that he, at 

 anv rate, has just that power, often lacking in German 

 men of science, of not allowing the details, while 

 giving them their full value, to obscure the main 

 issue. 



Of his original investigations, that on the origin 

 of the germ-cells in the Hydrozoa is specially in- 

 teresting, as it led him from the facts there observed 

 to formulate his greatest doctrine — the continuity of 

 the germ-plasm, and to found thereon a theory of 

 heredity. This doctrine had a much wider signifi- 

 cance than was at first thought. If it be accepted, 

 the onlv conclusion possible is that all varia- 

 tions — by this is meant inherited variations — 

 must be congenital, and that as the direct result of 

 this there can be no transmission of acquired char- 

 acters, that is to say, of such characters as are 

 acquired during the lifetime of the individual. Need- 

 less to say, the publication of this doctrine caused an 

 enormous sensation everywhere, but particularly so 

 among men of science and breeders. In spite of all 

 the jibes and sneers hurled at it, its effect on the 

 natural sciences has been deep and permanent, and, 

 however much modified, however much tampered 

 with, it forms the one firm basis of all modern views 

 of heredity. 



11 is thorough knowledge of both animal and vege- 

 table cytology helped him to place his theory of here- 

 dity on a surer basis, one might well venture to say 

 on a firmer foundation of fact than was possible for 

 most of his predecessors and many of his contem- 

 poraries. 



In the development of Darwinism Prof. Weismann 

 has taken a leading part, not only in gaining for it 

 in Germany an almost universal acceptance, but also 

 in explaining its real meaning to the world at large 

 and in freeing it from such traces of Lamarckism as 

 still r-xisted. 



Moreover, a style which is beautiful and at the same 

 time lucid, a persuasiveness which is equalled by few, 

 nnd a capacity for following a hypothesis to its logical 

 end, has made Prof. Weismann one of the foremost, 

 if not the foremost, exponent of all that is best in 

 Darwinism and in the teaching of Wallace. 



His views have exercised on evolution a far-reach- 

 ing influence, for they have been the direct cause, 

 and this must be peculiarly gratifying to Prof. Weis- 

 mann, of much of the recent research undertaken in 

 this subject. 



But a record brilliant as his has been is not sufficient 

 to fill the institute to overflowing, or to rouse such 



NO. 2l8o, VOL. 87] 



enthusiasm and affection for the director as is seen 

 there. This is purely due to the personality of Prof. 

 Weismann, to his geniality, and to the kindness with 

 which he guides the faltering steps, especially of 

 strangers within his gates. In fact, his Gemuthlich- 

 keit soon overcomes the diffidence of his students, and 

 at the same time rouses in them a regard and affection 

 which it is given to few teachers to gain. 



No student can work through a course in zoology 

 at Freiburg without being influenced by the enthu- 

 siasm, the earnestness, and the profound thorough- 

 ness he finds there, and gaining and retaining a feel- 

 ing of the deepest admiration for that veteran in 

 science, the director of the institute, Prof. Weismann. 



No better tribute can be paid to Prof. Weismann 

 than the affection in which he is held by his former 

 students, to whom the phrase, " Der Chef." calls up 

 so many pleasant memories, and no better proof of 

 this exists than the longing with which they look 

 back to the time spent within his halls. 



W. D. H. 



PREHISTORIC SOUTH AFRICA. 1 



MR. J. P. JOHNSON continues to make good 

 use of the opportunities his mining practice 

 gives him for the careful study of South African 

 geology and archaeology. The latest addition to his 

 series of short books is, like its predecessors, valu- 

 able from its record of carefully observed facts and 

 instructive illustrations. The subjects included range 

 from the period of the Zimbabwe ruins back to the 

 oldest of the stone implements, and perhaps even 

 older. Occasional remarks show that Mr. Johnson 

 had been a diligent collector of stone implements in 

 the south of England, so that he went to South Africa 

 as a trained observer. He has found in the rich 

 implement-bearing gravels there abundant scope for 

 his energies. He classifies the South African imple- 

 ments into three groups — Eolithic and two divisions 

 of Palaeolithic. No Neolithic implements have as yet 

 been found. He identifies as Eolithic a series of 

 implements collected from a gravel at Leijfontein, in 

 the Campbell Rand. He compares them with the 

 eoliths of Kent, which he accepts as probably of 

 artificial origin, though he admits that this conclu- 

 sion is still open to doubt. 



He gives two pages of sketches of these eoliths, 



and though they resemble some of the characteristic 



I Kent types, the illustrations are inadequate for any 



independent opinion as to their relations with the 



English "eoliths." 



The Palaeolithic implements are divided into two 

 groups — the Acheulic, which are generally of the 

 type which he has called amygdaliths, and the Solu- 

 tric, which are generally scrapers. He regards the 

 implements which he refers to the Solutric type as of 

 later date than the Acheulic. Some authorities, how- 

 ever, hold that both belong to the same period. Mr. 

 Johnson regards them as of different dates from the 

 evidence of their distribution. The Acheulic imple- 

 ments must, he thinks, be the earlier, as they are 

 found in older deposits, and none of the Solutric 

 sites have yielded any of the typical Acheulic forms. 

 He has collected Acheulic implements from seven or 

 more feet below the surface, and found some in 

 gravel that has been cemented to a hard conglomerate. 

 Manv of the Acheulic implements must be of consider- 

 able antiquity. They are abundantly distributed over 

 the plateau around the Victoria Falls, and Colonel 

 Fielden, who collected many there, is of the opinion 

 that they were deposited before the erosion of the 



1 "The Prehistoric". Period in ! 

 Pp. iv+89. (London : Longmans, i 



