IINNEAN SOCIETY OF LOKDON. XXlX 



part of our G-enera Plantarum ; but the labour it entails is long 

 and tedious, and we both of us are much impeded by other works 

 which we cannot suspend, as well as by other occupations which 

 unavoidably encroach upon our time. We confidently hope, 

 however, to send to press the third part, completiug the volume, 

 soon after the summer recess. 



Of T>e Candolle's Prodromus, since the detailed report I had 

 occasion to make of it in the Natural- History Review for October 

 1864, only one part has appeared, containing Cupuliferse and some 

 of the small allied orders by De CandoUe himself, with 327 species, 

 whilst other small orders, by Casimir de Candolle, comprise 87 

 species. Both had previously published detached papers on sub- 

 jects suggested in the course of working them up ; and De Candolle 

 has since inserted in the Actes de la Societe Helvetique a paper 

 on the venation of the leaves o^Fagus, comprising, amongst other 

 observations, one of those cautions to palaeontologists ia their de- 

 termination of genera from the fragment of a leaf which are now 

 arising from so many quarters. The genus EupJiorhia, by Boissier, 

 which I had mentioned as forming one part of the Prodromus, has 

 now been illustrated by the author in a handsome folio volume 

 containing 193 plates of the most interesting species. The printing 

 of the remainder of Euphorbiaceee, by J. Mueller of Argau, is, I am 

 happy to learn, far advanced, and we may at length hope to see 

 that vast, important, and difficult order rescued from the chaos 

 into which it has been thrown by independent publications in all 

 parts of the world. That Piperitae, by Casimir de Candolle, are 

 approaching completion, is shown by the forestallment of new 

 species inserted in the last part of Seemann's Journal of Botany, 

 and by a memoir on their anatomical structure, for the Actes de 

 la Societe Physique de Greneve, just received from the author. 



The last series of "Walpers's supplementary compilation has 

 been brought to a close by Carl Mueller, including all works he 

 had access to up to the year 1855. He announces a new series 

 for the ten years from 1856 to 1865, on a reduced scale, so as to 

 give a better chance of an early completion. On the other hand, 

 I regret to observe allusions to the state of the author's health 

 preventing any positive engagement as to the periods of issue. 

 Such a work is now so essential to the systematic botanist, as 

 giving a clue to where he is to search for published species, that 

 it is to be sincerely hoped the publishers will make such arrange- 

 ments as to ensure its continuation. 



Of monographs of detached groups we have (besides small con- 



