Bibliographical Notices. 219 



Bennett proceeds to examine in detail the various modifications 

 which take place in grasses in the number of these organs, and the re- 

 lation which these modifications severally bear to the composition of 

 the perianthium as indicated by its nerves. Adopting the well- 

 known hypothesis of Mr. Brown, before referred to, he endeavours 

 to show that " the structure of those grasses, in which deviations 

 occur from the ordinary number of stamina will be found perfectly 

 to accord with this view of the subject, and to afford perhaps some 

 additional arguments in its favour." With this object he passes 

 these deviations in review, noting especially those cases in Which a 

 posterior stamen is coincident with a middle nerve in the inner valve 

 of the perianthium ; and the rare exceptions in which either of these 

 structures is found unaccompanied by the other, for which exceptions 

 he endeavours in some degree to account. 



In the two succeeding articles Mr. Brown characterizes two new 

 genera of grasses, (^Sclerachne and Polytoc(i) selected to illustrate the 

 close affinity subsisting between Coix and Tripsacum, in the very 

 gradual transition between which they form two of the intermediate 

 stages. This transition is further assisted by another new genus, 

 Chionachne, founded on the Coix arundinacea of Willdenow, the distin- 

 guishing characters of which are pointed out. Of these several genera 

 Mr. Bennett enters into a detailed comparison, which clearly exhibits 

 the intimate connexion between them, as well as the near relation 

 of Tripsacum to Rottbcellia. They all belong to Mr. Brown's great 

 division of Panicece, together with Zea Mays, " which is also a nearly 

 related grass, being manifestly allied to Polytoca, and one whose 

 Paniceous character is so obvious that it is surprising that it should 

 not long ago have assumed its proper station in that tribe." Such 

 mistakes in natural affinities as have taken place with reference to 

 Coix, Tripsacum, and Zea, Mr. Bennett thinks, can only be attributed 

 " to the want of due attention to the very striking and important 

 character by which the Paniceee are connected together," and which 

 in the further subdivision of the order has been in a great degree neg- 

 lected and overlooked. 



The sixth article illustrates a genus of Grasses, Leptaspis, founded 

 by Mr. Brown in the ' Prodromus Florae Novse Hollandise' on the 

 species h^re figured, which is the Phnrus urceolatus of Roxburgh, 

 and on a New Holland species discovered by Sir Joseph Banks. Mr. 

 Bennett shows that the character of this genus has been much mis- 

 understood by later writers, who had had no opportunity of examining 

 either of the species ; and points out the differences in structure be- 



