188 Bibliographical Notices. 



according as the animal or vegetable element is predominant, they 

 can at one time exhibit an animal, at anotlier a vegetable life, without 

 altering their originally received form. 



In the genus Micromcga the author has made some observations, 

 which, if confirmed, are of very great importance, and more than any 

 other point will tend to establish the true position of these beings in 

 a natural system. He informs us that he has seen the naviculce or 

 frustules in this genus metamorphosed into green globular spores. 

 An Alga was discovered by Dr. Dickie at Aberdeen, which was al- 

 luded to before in this Journal, which seems to confirm these views ; 

 but Mrs. Griffiths, than whom no one is able to form a better judge- 

 ment, or whose opinion is entitled to greater weight, and Mr. llalfs 

 are inclined to think that the appearance is produced by parasites of 

 the genus Cocconeis and similar productions. The point cannot 

 therefore be received at present as established, though we ourselves 

 are persuaded that Dr. Kiitzing's views will be found correct. 



Our British coasts abound in species of Schizonema and Micro- 

 mega, and we regret much that Dr. Kiitzing had not the command 

 of better materials as regards the British species. We fear that some 

 communicated by Binder were not authentically named, and this is 

 the more to be regretted, as far the greater part of the species de- 

 scribed in Harvey's ' Manual ' are well understood by the author, 

 and especially by Mrs. Griffiths, who has so largely contributed to 

 the illustration of the genus. In this indeed our friend Dr. Kiitzing 

 is not to be blamed, but the writer of the present remarks is rather 

 inclined to reproach himself for not having, by some inadvertence, 

 communicated specimens when it was in his power to do so. Our 

 only reason for calling attention to the subject is to induce due cau- 

 tion in the examination of this part of the work. 



We trust that it will receive the support it deserves, and we have 

 little doubt that it will do so, as it is no less indispensable to the 

 geologist than to the botanist. 



The Botany of the Voyage o/H.M.S. Suljjhnr. Edited by R. B. Hinds, 

 Esq. The Botanical descriptions by G. Bentham, Esq. Nos. 2, 

 3,4. 



We have already noticed the first number of this valuable work, 

 of which three additional numbers have recently reached us. The ex- 

 pectations which were raised by an examination of that number are 

 fully answered by these. Indeed it seems to us that the plates have 

 improved in the successive numbers. The description of the plants of 

 California is concluded, and the remaining portion is occupied with 

 those of Western Tropical America. 



Several new genera are described and very many new species. It 

 is quite unnecessary to add that these descriptions possess great ex- 

 cellence ; the name of Bentham is a sufficient security on that point. 



Such books as that now before us are the strongest proof of the 

 value of the assistance of late afforded by Government for the publi- 

 cation of the results in natural science obtained by officers on board 



