37 6 



THE POPULAR SCIENCE MONTHLY, 



The most remarkable part of this vol- 

 ume, however, is that relating to the fossil 

 fish of the Devonian Age. This period, as 

 is well known, has long been called the 

 " Reign of Fishes," from the great variety 

 of singular and grotesque forms of fish-life 

 which then appeared and peopled the an- 

 cient seas. The greatest share in bringing 

 to light this extraordinary series of by-gone 

 types was borne by Hugh Miller, whose 

 discoveries in the " Old Red Sandstone " of 

 Scotland have won for him imperishable 

 fame in the annals of science. The con- 

 tinuation, on this continent, of Miller's dis- 

 coveries abroad, is here given to the world ; 

 and it is no less remarkable, perhaps indeed 

 more so, than were his. The series of fish 

 here described forms an extraordinary ad- 

 dition to our knowledge of the life of the 

 past. The Devonian waters that spread 

 over what is now the greater part of Ohio 

 were inhabited by a strange race of literal 

 sea-monsters, singular in form and gigantic 

 in size, plated and mail-clad, and bearing all 

 manner of elaborate weapons for offense 

 and defense. Among them we may refer 

 te the tribe of Chimaeroids, allied to the 

 sharks, now represented only by a few rare 

 species, and which, though well known to 

 have existed in later formations, has never 

 before been discovered in palseozoic rocks. 

 Dr. Newberry has described the new genus 

 Rhynchodus, with several species belonging 

 to this group. Still more singular, how- 

 ever, are several genera of ganoid fish, of 

 which only one or two can be referred to 

 here. One of these is Onycliodus, which 

 carried at the extremity of its lower jaws, 

 where the two rami meet, a vertical set of 

 long, radiating teeth, projecting like the 

 piercing prow of an iron-clad ram. This 

 form is wholly novel. Another is Deinich- 

 ihys, the giant of the period, whose tremen- 

 dous jaws, shaped like sled-runners, were a 

 couple of feet in length ; while the bony 

 buckler that covered the back was from 

 one to two inches in thickness ! 



But time would fail us to dwell on these 

 interesting accounts ; and we can only ex- 

 press our gratification that so much impor- 

 tant discovery is now announced and record- 

 ed in a permanent form t and congratulate 

 both the gentlemen of the survey and the 

 people and government of Ohio on this 



great work now so auspiciously approaching 

 its close. 



Autobiography op John Stuart Mill. 

 New York : Henry Holt & Co. 313 pp., 

 8vo. Price, $2.25. 



This is said to be the book of the sea- 

 son, and it is creditable to the season that 

 it is so, for it is a volume of deep and va- 

 ried interest, as well as of important instruc- 

 tion. Without any dramatic incident or ex- 

 ternal adventure, the earnest attention of 

 the reader is sustained by a delineation of 

 the quiet career of a man of thought. After 

 all, there is nothing that so concerns us, 

 with regard to a great man, as how his 

 greatness was reached. Mr. Mill has con- 

 ducted no campaigns, explored no new 

 countries, guided no political administra- 

 tions, but through his writings he has in- 

 fluenced the thought of his age, in direc- 

 tions where thought issues in action, and 

 his influence may thus have been deeper than 

 if he had wielded the more obtrusive and 

 conspicuous agencies by which men are af- 

 fected. Obviously, in writing his own life, 

 Mr. Mill did not feel that he had any great- 

 ness to take care of, and so he gives a 

 faithful account of his development, taking 

 the reader completely into his confidence, 

 relating his experiences, and offering his 

 opinions and self-criticisms with a candor 

 and unreserve that are quite remarkable. 

 Those who have become interested in Mr. 

 Mill's ideas, and through them in the man, 

 will devour the book with eager curiosity ; 

 and those who have not, can hardly fail to 

 be incited by its perusal to the study of his 

 works. We by no means agree with all 

 that Mr. Mill has promulgated, and have giv- 

 en, in another place, the reasons for dissent- 

 ing from some of his doctrines ; but, while 

 holding him as not above criticism, and as 

 having fallen into educational error from 

 the very greatness of his attainments, we 

 do not hesitate to acknowledge our indebt- 

 edness to him as a great leader of liberal 

 thought in the present age. His autobiog- 

 raphy is valuable as a record of his own 

 mental unfolding ; but, beyond this, it has 

 great value as a history of the rise and 

 progress of liberalized opinion in England 

 within the last thirty years, in the promo- 

 tion of which Mr. Mill had so eminent a 



