Notices of New Books. 4975 



earnest have been the labourers in this enticing field, and propor- 

 tionately encouraging have been the results. The indefatigable in- 

 dustry of Professor Owen, conspicuous in every department of our 

 science, has, by his invaluable analysis of the vertebrate skeleton, not 

 only remodelled the nomenclature of the osteologist, but placed in the 

 hands of the Geological student a light wherewith to guide his steps 

 amid the darkness of departed worlds. The improvements in our 

 microscopes, and the zeal of our microscopists, have much advanced 

 our knowledge of the Infusorial organisms. The researches of Van 

 Beneden and Siebold, relative to the embryogeny of parasitic worms, 

 open before us a new field of research, while the observations of Steen- 

 strup, Dalyell and Agassiz on the 'alternation of generations' among 

 the Hydriform Polyps and Acalephae, promise results of the utmost 

 interest to the naturalist." 



Again, directly we commence the work, which really begins at 

 Chapter IT., we find that the second edition is a new work, and one 

 which, in a great many instances, brings down the wave of discovery, 

 if I may be allowed to use such an expression, almost to the day of 

 publication. This is as it should be : whatever we do in science we 

 should at least master what has been previously done ; to adopt the 

 views or to vouch for the supposed discoveries of another is a matter 

 of mere option ; to display ignorance of them is inexcusable. 



In illustrations there is also a great improvement ; nearly a hundred 

 new ones are added; and many of those, which serve to illustrate other 

 of Mr. Van Voorst's publications, have been omitted. Some of the 

 worst entomological illustrations still remain; those at pp. 384, 390 

 and 403 have neither truth nor taste to recommend them ; the flea at 

 p. 350 appears to vary in the number of tarsal joints from eight as a 

 maximum to five as a minimum : on the contrary, the anatomical 

 illustrations of this part of the work are good and taken from the best 

 sources. 



The letter-press is always pleasing and for the most part explicit, 

 lucid and trustworthy. Two faults, however, become apparent to the 

 practical naturalist : first, that Mr. Jones has not always gone to the 

 fountain-head for knowledge ; secondly, that he has not always gone to 

 those streams nearest the fountain-head, where the knowledge is most 

 pure and undefiled. However plainly these facts may present them- 

 selves to the mind, it is neither easy nor pleasant to convince the reader 

 of the justice of the assertion ; still the attempt must be made. 



First, then, as to not drawing or describing from the objects them- 

 selves, or, in other words, going to the fountain-head for knowledge : 



