420 Bibliographical Notices. 



tions and alterations. The book opens with a short treatise on the 

 physical geography of the sea, in which we have a picturesque gene- 

 ral description of the sea, its waves, tides, and currents, and their 

 causes, and of the " aerial and terrestrial migrations of the waters," 

 the latter including an account of the winds and of the circulation 

 of the water evaporated from the ocean through the atmosphere to 

 the surface of the land and back again to its source. To this section 

 of the book the author has added two new chapters, containing de- 

 scriptions of some marine caves and of certain marine constructions, 

 chiefly lighthouses. 



It is to the second part of his work, which treats of the inhabitants 

 of the sea, that the author has evidently devoted his chief attention ; 

 and he has succeeded in giving a good popular account of the prin- 

 cipal forms of marine animals and plants. In comparing this section 

 of Dr. Hartwig's book with that in the first edition, we find that, 

 without making it very technical, he has put it in such a form as to 

 convey a very fair general notion of the modern classification of 

 animals and of the peculiarities characteristic of the chief types be- 

 longing to each great group which is represented among the popula- 

 tion of the sea ; the chapter on the Crustacea has been reconstructed 

 and made much fuller, especially with respect to the metamorphoses 

 which most of those animals undergo ; a brief account of some 

 marine Rotifera has been appended to the chapter on marine worms ; 

 the description of the Mollusca has been considerably added to and 

 improved ; and the account of the Coelenterata has been entirely re- 

 written on quite a new plan. We notice also that the Diatoms 

 have been removed from their former position among the Infusoria 

 and placed with the marine plants. In the chapter on the geogra- 

 phical distribution of marine life, Dr. Hartwig has availed himself 

 of the results obtained by recent researches in the abyssal waters 

 of the Atlantic. 



The third and concluding part of the book is devoted to a brief 

 sketch of the history of maritime discovery, with which we have 

 nothing to do here, but which will doubtless enhance its value in the 

 eyes of those young readers for whose delectation it is particularly 

 designed. On the whole we are not acquainted with any better gift- 

 book than Dr. Hartwig's volume, almost the only defect of which 

 consists in the miserably small size and generally poor execution of 

 many of its numerous natural-history illustrations. We notice, 

 however, as a sign of better things, that most of the new woodcuts 

 are on a larger scale and fairly executed ; so that we may hope 

 in course of time, as more editions are called for, the paltry little 

 old blocks will be gradually eliminated. 



Outlines of Natural History for Beginners, being Descriptions of a 

 Progressive Series of Zoological Types. By H. Alleyne Nicholson, 

 M.D. &c. 12mo. Blackwood : Edinburgh and London, 1873. 



Dr. Nicholson has added one more to his already long list of 

 educational works ; but we do not think that his ' Outlines of 



