Oct. 4, 1877] 



NATURE 



491 



mammal was doubtless plantigrade, and certainly five-toed. 

 Many of the early tertiary forms show this feature, which is still 

 seen in some existing forms. This generalised foot became 

 modified by a gradual loss of the outer toes and increase in size 

 of the central ones, the reduction proceeding according to sys- 

 tematic methods, differing: in each group. Corresponding 

 changes took place in the limb bones. One result was a great 

 increase in speed, as tlte power was applied so as to act only in 

 the plane of motion. The best effect of this specialisation i; 

 seen to-day in the horse and antelope, each representing a 

 distinct group of ungulates with five-toed ancestors. 



If the history of American mammals, as I have briefly 

 sketched it, seems as a whole incomplete and unsatisfactory, we 

 must remember that the genealogical tree of this class has its 

 trunk and larger limb; concealed beneath the dt'bris of mesozoic 

 time, while its roots doubtless strike so deeply into the paleozoic 

 that for the present they are lost. A decade or two hence we 

 shall probably know something of the mammalian fauna of the 

 cretaceous, and the earlier lineage of our existing mammals can 

 then be traced with more certainty. 



The results I have presented to you are mainly derived from 

 personal observation, and since a large part of the higher verte- 

 brate remains found in this country have passed through my hands. 

 I am willing to assume full responsibility for my presentation of 

 the subject. 



?"or our present knowledge of the extinct mammals, birds, and 

 reptiles of North America, .science is especially indebted to 

 Leidy, whose careful, conscientious work has laid a secure 

 foundation for our vertebrate paki^ontology. The energy of 

 Cope has brought to notice many strange forms, and greatly 

 enlarged our literature. Agassiz, Owen, Wyman, Baird, flitch- 

 cock, Deane, Emmons, Lea, Alien, Gibbes, Jefferson, DeKay, 

 and Harlan deserve honourable mention in the history of tliis 

 branch of science. The .South American extinct vertebrates 

 have been described by Lund, Owen, Burmeister, Gervais, 

 Huxley, Flower, Desmarest, Aymard, Pictet, and Nodot 

 Darwin and Wallace have likewise contributed valuable informa- 

 tion on this subject, as they have on nearly all forms of life. 



In this long history of ancient life I have said nothing of what 

 life itself really is. And (or the best of reasons, because I know 

 nothing. Here at present our ignorance is dense, and yet we 

 need not despair. Light, heat, electricity and magnetism, 

 chemical affinity, and motion are now considered different forms 

 of the same force ; and the opinion is rapidly gaining ground 

 that life, or vital force, is only another phase of the same power. 

 Possibly the great mystery of life may thus be solved, but whether 

 i'. be or not, a true faith in science admits no limit to its search 

 for truth. 



THE GERMAN ASSOCIATION AT MUNICH 

 'PHE fiftieth meeting of the German Association of Naturalists 

 ■'■ and Physicians began on .September 17 by a large assembly 

 of visitors in the old Town Hall at Munich. The meeting 

 thi 5 year assumed quite a national character. Although in the 

 programme its scientific character was principally considered, 

 and .pleasure trips, banquets, &c., had been reduced to the 

 most modest proportions in comparison with former years, jet 

 the aspect of the city of Munich, and of all the edifices that 

 were in any way connected with the meeting, was a festive one. 

 Some 2,000 visUors had arrived, and the Town Hall on the night 

 of the 17th W3s crowded to suffocation. The authorities of the 

 city gave a grand Keller-Fest in honour of the visitors on the 

 20th, which was attended by over 5,000 guests. 



Tlie fir.>t general meeting was opened by Prof von Pettenkofer 

 on the morning of the iSthinst. In a short address the professor 

 announced that His Majesty the King iad intended to send his 

 royal greeting to the assembled men of science through H.R.H. 

 Duke Carl Theodor, of Bavaria (brother to the Empress of 

 Austria), I ut that the duke had suddenly been called to Dresden 

 through the death of the dowager Queen of Saxony. In his 

 absence His Majesty had intrusted the secretaries with this 

 honourable message. After other congratulations Dr. von 

 Pettenkofer delivered his inaugural address. He reminded 

 the assembly that the present was a jubilee meeting, and 

 then gave a retrospect of the growth of the Association 

 since its foundation. The first meeting took place at Leip- 

 zig on September 18, 1822, when, following the invitation 

 of Prof. Oken, twenty scientific men assembled and founded 

 the Society. A paragraph of the statutes prescribed that 

 the meetings should always begin on September iS, and 

 should last several days. Under the political circumstances of 



that time and with the means of conveyance then existing the 

 modest number of twenty members was considered a fair begin- 

 ning. The next meeting occurred at Halle with thirty-four 

 members, the third at Wurzburg with thirty-six, the fourth at 

 Frankfort-on-Maine with no, the fifih at Dresden with 116, the 

 sixth at Munich wiih 156, and the .seventh at Berlin in 1S28, 

 when 464 members were present. The Association steadily 

 increased and the meetings were helrl annually unless prevented 

 by war or epidemics. The last meeting at Hamburg numbered 

 over 2,000 members. Little by little a division of labour took 

 place, and out of the seven original sections twenty-five have 

 now resulted. 



After speaking of the progress made by man as compared with 

 the lower animals. Pro'. Pettenkofer said — If knowledge is power, 

 and nobody will doubt this, then amongst sciences natural science 

 is certainly destined to play a great part, perhaps the greatest, in 

 the history and culture of mankind. . . . Natural science has but 

 to look for facts and truths, and need never busy itself about 

 the immediate practical application ot what has been found, 

 because for them alone it deserves the sympathy of the entire 

 civilised world, and the means necessary for its culture and de- 

 velopment. No investment of capital bears higher interest. 

 Finally, the speaker recalled the memory of Prof Ludwig 

 Lorenz Oken, the founder of the association and the .author of 

 the statutes which, with but a single and trifling exception are 

 still in force to-day. He praised the patriotism of Oken, and 

 regretted that he died before the reestablishment of the United 

 (ierman Empire. 



At the end of the address, the assembly, at the request of Dr. 

 von Pettenkofer, rose from their seats in honour of the memory 

 of Oken. 



Then followed the first scientific lecture, which was delivered 

 by Prof Waldeyer (Strassburg). He spoke on Karl Ernst von 

 Paer and his Influence on Natural Science, giving an elaborate 

 memoir of the late great naturalist, to whom we owe many of 

 the bases of the present theory of evolution. Prof. Dr. Haeckel 

 then delivered his address On the Evolution Theory at the Present 

 Time, which we give elsewhere. 



At the second general meeting, on the 20th, the choice of a 

 place of meeting was made for next year, Cassel being selected, 

 with Doctors Stilling and Gernau as secretaries. Duke Carl 

 Theodor of Bavaria, himself an able ophthalmologist, took the 

 chair in lieu of Dr. Pettenkofer, and again welcomed the 

 assembly, in the name of the kingdom of Bavaria, in an inter- 

 esting speech. Then followed the address of the eminent 

 botanist, Prof Dr. Nageli, of Munich, " On the Limits of Natural 

 Knowledge." He pointed out that many naturalists, when asked 

 about the limits of natural knowledge, and thinking a solution 

 by principles insufficient, simply reply that faith begins where 

 knowledge ends. Humanity fa^es the whole of nature, masters 

 new domains constantly by dint of meditation ; the empire of 

 knowledge thus always increases in extent, and that of faith 

 decreases as constantly. But this solution does not satisfy our 

 interest. We would wish to know particularly whether the 

 limits of natuial knowledge can be determined at all, and how 

 far we can penetrate into nature. The solution of this question 

 is determined by three eruditions: — (i) By the condition and 

 capacity of the investigating Self; (2) by the condition and 

 accessibility of nature ; and (3) by the demands which we 

 make from knowledge. With regard to the first point, the un- 

 doubted fact is decisive that our power of thinkmg, in whatever 

 condition it may be, can but give us nature as we perceive her 

 with our five senses, and even this again not in her full extent 

 and completeness, but only as far as we perceive her in the 

 present. We see and hear only what is in the present ; now as 

 the organs of our senses are more or less sensitive for the 

 one or the other perception, Darwin's ingenious idea that in 

 nature only so many phenomena attained lull development as 

 were useful to the individual bearer, is fully justified ; on the 

 other hand it is very probable that many molecular forces exist 

 of which we have no idea, simply because we cannot perceive 

 them with our senses. The limited capacity of the I allows 

 us only an extremely fragmentary knowledge of the universe. 

 With reference to the second point, the condition and accessi- 

 bility of nature, we can easily perceive the limit ; for man it 

 rests in space and time. The infinity of space and time, and its 

 consequences, are insuperable for us, and nature is everywhere 

 uninvestigable where she becomes eternal or infinite, and there. 

 fore she can never be intirely investigated. The naturalist must 

 therefore always bear in mind that all his investigations are re- 

 stricted to natural limits, otherwise he will lose himself in ground- 



