Stt 



REVIEW. 



The Nature -printed British Sea- Weeds ; a history accompanied 

 by figures and dissections of the Alga of the British Isles. 

 By William Grosart Johnstone, F.B.S.E., and Alex- 

 ander Croall, A.B.S.E. Nature-printed by Henry 

 Bradbury. Vol. I. Rhodospermeae, Fam. I — IX. 

 London : Bradbury and Evans. 



The success of the production of the British ferns by the 

 new process of nature-printing has encouraged Mr. Brad- 

 bury to attempt a much larger family of plants. The sea- 

 weeds, on account of their membranous nature, presented 

 peculiar facilities for representing them by nature-printing ; 

 and in this volume we have an instalment of a work which is 

 to be devoted to the whole of the British species of this 

 family. 



The process of nature-printing, which has the power of re- 

 pi'oducing with great accuracy the outline and impressions 

 on the surface of plants, is effected by a kind of modelling. 

 The plant is first impressed upon a sheet of soft metal, and 

 from this a copper impression is taken by means of the 

 electrotype process. Into these copper plates the paper on 

 which the plants are produced is pressed, the plate having 

 been previously prepared with colour according to the colour 

 of the plant. This process, which is so well adapted to 

 secure the natural outline and superficial markings of plants, 

 cannot to any extent be employed in the reproduction of 

 minute points of structure, especially where this involves 

 anything more than can be obtained from a surface im- 

 pression. Under these circumstances, the authors in this 

 work have added to each plate drawings of the structure 

 and microscopic characters of the fruit of the various species 

 of algae represented in the plates. It is this part of the 

 work that will be found more especially interesting to the 

 microscopic observer. Every species of sea-weed has its 



