1870.] Notices of Scientific Works. 79 



sufficient to carry us down exactly the twenty steps ; it is evident 

 that the Will was set in motion to descend the imaginary twentieth 

 step with as much force as it was at the first step. But the best 

 illustration of unconscious voluntary action is perhaps afforded by 

 the motion of the fingers in writing, where the warmest advocate of 

 the theory of habit can hardly maintain that the action is entirely 

 consensual ; and the storage of the Will hypothesis is evidently in- 

 adequate to account for each separate motion of the fingers, which 

 must require a distinct action of the Will, exercised perfectly uncon- 

 sciously to ourselves. The lateral motion of the eye-balls, again, 

 which takes place in reading, is one evidently entirely under the 

 control of the Will, and is yet performed with the most perfect 

 unconsciousness. 



We appear to have dwelt rather on those points in which we 

 differ from Mr. Murphy than on those in which we agree with him. 

 There is, however, much in these two volumes that will interest 

 every student of Biology and of Psychology, and not a little that 

 must commend itself to the attention of every man of science. 

 Whatever acceptance his views may meet with in the scientific 

 world, it is impossible not to acknowledge the fairness and modera- 

 tion with which he has brought them forward, and the ability with 

 which he has supported them by logical argument and by a large 

 array of facts. 



JEFFEEYS' BEITISH CONCHOLOGY * 



From the various reports which have from time to time appeared 

 in these pages, of the dredging expeditions of the author of this 

 work, as well as from the notice of the second volume of a por- 

 tion of the work itself, which is to be found as far back as in our 

 first volume, our readers will have become well acquainted with 

 the active labours of Mr. Grwyn Jeffreys. The publication of the 

 work has extended over seven years, and all we can attempt to do 

 here is to give a brief outline of its contents. 



The first volume deals with "land and fresh- water shells," 

 the remaining four with " marine shells ; " but from this it must 

 not be inferred that the author's labours have been confined to the 

 description of shells alone. The book is an excellent and complete 

 treatise on the Natural History of British Mollusca, containing 

 not only accurate descriptions of the various genera and species in 

 their zoological order, but accounts of their British habitat, as welL 



* ' British Conchology ; or, an Account of the Mollusca which now inhabit the 

 British Isles and the Surrounding Seas.' In 5 volumes (commencing 1862 and 

 ending 1869). Illustrated with coloured and plain plates. By John Gwyn 

 Jeffreys, F.R.S., F.G.S., &c. Van Voorst. 



