Bibliographical Notices. 173 



extends itself, while part of the sperm atozoal contents of the 

 original sac also pass into the newly-formed cavity. The super- 

 added portion continues to increase in size, and soon acquires a 

 form exactly resembling that of the original sac, so that each goiio- 

 phore now presents a double sac, one superposed upon the summit 

 of the other. Into this second sac the original one continues to 

 discharge its contents, and. gradually contracts as the terminal 

 one enlarges. In the terminal sac the spermatozoa attain to 

 their full maturity, and. ultimately, in the shape of pyriform 

 caudate corpuscles, escape from it by an aperture in its summit. 



BIBLIOGRAPHICAL NOTICES. 



British Wild Flowers. Illustrated by J. E. Sowerby. 8vo. 

 London : Van Voorst, I860. 



A reissue of this useful book has been commenced by Mr. Van 

 Voorst in monthly parts. The book consists of 80 coloured plates, 

 containing figures of a portion of each of 1600 British flowering 

 plants. These figures are very nicely executed, and are parts of the 

 complete representation of the plant which is to be found in the well- 

 known ' English Botany ' or its Supplement. In most cases they 

 amply fulfil the purpose for which they are intended. Being clear, 

 and usually characteristic of the plants, they will be found convenient 

 for removing temporary difficulties caused by want of memory or an 

 imperfect knowledge of allied species. Such a book is sure to be 

 useful, and seems to supply a want that has long been felt. 



Certainly there are cases in which we should have made a slightly 

 different selection from the original plate, or added an outline of 

 some organ not there delineated : the judgment of the artist or his 

 adviser differed considerably from ours in the estimation of what 

 would be most useful to the student. But that is a very small 

 fault ; for it only renders the book a little less useful than it might 

 have been. 



We do not think much of the letterpress which accompanies the 

 plates ; and, indeed, its author claims very little credit for it. No 

 person must attempt to use it as a descriptive flora. If the descrip- 

 tions had been left out, much space would have been saved, and the 

 value of the book not diminished. All the letterpress requisite is the 

 name of the plant and a few references to descriptions by recognized 

 authors. 



We wish that all the plants of which figures have appeared in the 

 ' Supplement to English Botany ' had been inserted in these plates. 

 Those contained in vol. iv. of the 'Supplement' seem to be omitted ; 

 and as they consist chiefly of the more recent discoveries, or what 

 are called critical plants, their want will often be felt. Mr. Sowerby 

 may perhaps have done well in giving figures of some plants included 

 bv mistake in ' English Botany/ in order that his ' Wild Flowers ' 



