Ixxiv TROCEEDINaS OF THE 



the general distribution of the vegetable kingdom, with the addition, 

 however, of a perfectly distinct centre for the characteristic Austra- 

 lian flora, and perhaps also for that of South Africa. 



Leuckart's work on the Parasites of Man has now reached the 

 second part of vol. ii. Dr. A. Schneider has published a monograph 

 of Nematodes, exhibiting, in a striking manner, a . combination of 

 accurate research and felicitous generalization. Semper's beautiful 

 work on Holothuria, forming the first thi'ee parts of the scientific 

 results of his travels in the Philippine Islands (Ueisen in dem 

 Archipel der Philippinen, wissenschaftliche Resultate), although 

 professing only to give the details of his own observations, is, in 

 reality, an almost exhaustive monograph of the group. The histo- 

 logy of the Coelenterata has been treated by Kolliker in his ' Iconcs 

 histologicse ; ' and Oscar Schmidt has published a second supplement 

 to his ' Sponges of the Adriatic,' containing a discussion of Bower- 

 bank's genera, and also a part of his great work on Infusoria. 



The Zoology of the voyage of the ' Novara,' consisting neither of 

 monographs nor of faunas, nor yet of any exhaustive treatise upon 

 any one zoological subject, is simply a repertory of detailed descrijj- 

 tions, and, however useful these may be as additions to our stores of 

 species known, need scarcely have been mentioned here, but for the 

 beauty of the illustrations with which some of the parts are accom- 

 panied. The parts recently published are : — Fish, by Kner ; Ileptilia 

 and iVmphibia, by Steindachncr j MoUusca, by v. Frauenfeld ; Lcpido- 

 ptera (parts 2 and 3 completing the Butterflies), by Felder; Hemi- 

 ptera and Neuroptera, by G. L. Mayr and F. Brauer; and Annelida, 

 by Grube. 



In Botanj', Germany has supplied us Avith some general speculative 

 essays which I have not as yet had time to go over. Such are : — 

 Ernst Krause's Systematic Botany in relation to morphology, men- 

 tioned in the Bulletin de la Soeiete Botanique de France for 1866 ; 

 Nageli's speculations on hybridism and on species, in the Proceed- 

 ings of the Hoyal Academy of !Munich ; besides others by other 

 writers in the Botanische Zeitung and other periodicals, many of 

 them taking up more or less of Darwinian principles. 



Hofmeister's Handbook of physiological Botany, mentioned in my 

 address of 1866, is, contrary to expectation, not yet completed, and 

 the detached papeis on various points of vegetable physiology are 

 far too numerous to be here particularized ; I would, however, call 

 your attention in a few words to Hildebrand's ' Geschlechterver- 

 theilung bei den Pflanzen,' or distribution of sexes in plants. This 



