4 REVIEWS. 



The generic characters are very long, — that of the first genus, for 

 instance, Allamanda, occupies 54 lines, and contains details which cannot 

 be essential to the genus, nor can have been verified in the majority of 

 species ; such, for instance, as " Rostellum . . . circa quintuplo cotyle- 

 donibus brevius," when the seeds have only been seen in three out of ten 

 species. It is true that imperfectly known species must often be referred 

 to a genus without verifying all its characters, subject to a subsequent 

 removal, if found to differ in .essential points ; but it surely cannot be 

 intended that any species the radicle of whose embryo should be |rd, 

 instead of -ith the length of the cotyledons, should on that account alone 

 be generically separated from other Allamandas. 



Practically, however, these generic characters must be taken as de- 

 scriptive, rather than diagnostic; and the inconvenience of their great 

 length for distinctive purposes is, in the present work, obviated by an 

 excellent synoptical table of genera, remarkably clear, both as to matter 

 and type. But no such assistance is afforded in the case of species. In 

 the larger genera, even after their subdivision into groups, there remain 

 series of ten, twelve, or more species, without any contrasted characters, 

 to guide the reader, but such as he can glean from so-called diagnoses, 

 which, far from being confined to the Linnean limits of twelve words, 

 have an average length of twelve to fourteen lines, and are, in fact, de- 

 tailed descriptions in the ablative case, of almost all characters, except 

 colour and dimensions, which, in true orthodox style, are specially re- 

 served for a separate paragraph in the nominative case. This is a 

 growing evil in almost all modern systematic works, and for which we 

 see no remedy but a rigid return to the Linnean rule, accompanied by 

 repeated sectional subdivisions, or a total abandonment of the system of 

 technical diagnoses, substituting synoptical tables, followed by detailed 

 descriptions. 



In the generic arrangement of the Brazilian Apocynaceae, Dr. Miil- 

 ler appears to have much improved on his predecessors. The general 

 division of the order into two main groups, founded on the structure of 

 the anthers, is, we believe, new. It appears natural; and, if duly vere- 

 fied on the Asiatic, as well as on the American genera, is in every way 

 satisfactory. The tribes are, in other respects, nearly those of the Pro- 

 dromus. We are glad to see, also, that several genera which we had 

 already set down as not natural, are here suppressed. Collophora 

 (Mart), and Hortsmania (Miq.), are identified respectively with 

 Couma (Aubl.), and Condylocarpon (Desf.), Peschiera and Bonafousia 

 (A. DC), are reduced to Tabernaem on tana; Eobbia (A.DC.),toMalouetia, 

 and Thysanthus (Benth.), to Porsteronia. On the other hand, eight 

 new genera are proposed, besides three more South American, but not 

 Brazilian genera, which the author has described at the same time, and 

 published in Mohl and Schlechtendahl's Botanische Zeitung, 1860, p. 

 21. Of these eleven genera, Elytropus, founded on a Chilian plant, 

 appears to be very distinct. Zschokkea, allied to Ambelania, Couma, 

 and Hancornia, must be maintained, so long as the three latter are 

 kept distinct, although it is not improbable that on a careful comparison 



