ON THE PROGRESS OF SCIENCE. V 



on the Testudinata or Tortoises, have been published, illustrated by 

 thirty-four plates. An important part of these volumes is an intro- 

 ductory essay, which has been re-published separately in an 8vo 

 volume. Louis Agassiz's ' Essay on Classification,' embraces the 

 whole range of the subject, which he treats in a wider and more 

 comprehensible and less mechanical manner than has hitherto been 

 done. But while I thus praise the work, and the manner in which it 

 is treated, and agree with a great many of the positions he has taken 

 up, I must warn its readers that some subjects are treated in a way 

 Prof. Agassiz will not be able to maintain ; and that, to those who are 

 unable or unwilling to think for themselves, the author's reputation 

 will prove a guarantee not altogether to be trusted. It must be 

 studied with great care and great caution. Nevertheless, I look upon 

 it as the remarkable book of the year. There is another work, upon 

 a similar subject, advertised, from which we may expect some curious 

 reasonings, ' On the Origin of Species and Varieties,' by Charles 

 Darwin." 



At the opening of the Geological section, Sir Charles Lyell 

 reviewed the subject of the " Geological Age of Man," with special 

 reference to the researches which have been recently brought before 

 the public. 



" No subject," he said, " has lately excited more curiosity and gen- 

 eral interest among geologists and the public than the question of 

 the antiquity of the human race, whether or no we have sufficient 

 evidence to prove the former coexistence of Man with certain ex- /fL0* 

 terrwl mammalia, in caves, or in the superficial deposits commonly 

 called " drift,' or ' dejluvium.' For the last quarter .of a century, 

 the occasional occurrence, in various parts of Europe, of the bones 

 of man, or the works of his hands, in cave-breccias and stalactites, 

 associated with the remains of the extinct hysena, bear, elephant, or 

 rhinoceros, have given rise to a suspicion that the date of man must 

 be carried further back than we have heretofore imagined. On the 

 other hand, extreme reluctance was naturally felt, on the part of 

 scientific reasoners, to admit the validity of such evidence, seeing that 

 so many caves have been inhabited by a succession of tenants, and 

 have been selected by man as a place not only of domicile but of 

 sepulture, while some caves have also served as the channels through 

 which the waters of flooded rivers have flowed, so that the remains of 

 living beings which have peopled the district at more than one era 

 may have subsequently been mingled in such caverns, and confounded 

 together in one and the same deposit. The facts, however, recently 

 brought to light during the systematic investigation, as reported on by 

 Falconer, of the Brixham Cave, must, I think, have prepared you 

 to admit that skepticism in regard to the cave-evidence in favor of 

 the antiquity of man, had previously been pushed to an extreme. 

 To escape from what I now consider was a legitimate deduction from 



1* 



