LINNEAK SOCIETY OF LONDON. 57 



the Classification of the Creodonta" (American Naturalist, 1881), 

 a group supposed to be intermediate between Carnivora and 

 Marsupials. The same author describes the feet of the little- 

 known extinct Toxodon (said by him to be Proboscidean in cha- 

 racter) ; and also describes a Lemurine animal, Anaptomorplms 

 Jiomunculus, with a dentition like that of Anthropoid apes. 



Part 1 of Mr. Dobson's ' Monograph of the Insectivora ' has 

 been issued in this year. It ])romises to be a valuable work ; 

 already the author has shown, inter alia, that the "West-Indian 

 Solenodon has nothing to do with the Centetidse of Madagascar, 

 as had always been supposed before. 



The placenta of Mammals still offers large scope for research. 

 Prof. E. M. Balfour has thrown much light on the real signifi- 

 cance of the various forms of Placenta by his paper on the " Evo- 

 lution of the Placenta and its bearing on Classification;" the 

 most important point being the separation of the discoid pla- 

 eentffi into two widely remote groups, viz. the " protodiscoidal " 

 and the " metadiscoidal," the latter containing only Man and the 

 Simise. The placentation of the Marsupials is still in as much 

 obscurity as it ever was. Prof. Chapman, of Philadelphia, has 

 offered some observations on the placentation oi Macropusm the 

 ' Trans. Ac. Nat. Sci. Philadelphia,' 1881 ; but it is indeed sur- 

 prising that, with all our zoological gardens and successful 

 breeding of these animals, no more definite knowledge is attained. 



A work of a comprehensive character, of which the first part 

 has appeared in 1881, is the magnificently illustrated folio volume 

 by Prof. Gustav Eetzius, ' On the Auditory Organ of the Verte- 

 brata.' This is one of the most thorough and masterly treatises 

 of the day, the comparative anatomy of the microscopic tissue- 

 elements, as well as of larger parts, being most fully consi- 

 dered and set before the reader. 



Hasty and full of gaps as this summary is, it would be alto- 

 gether ' too partial were a notice omitted of the ' Vergleich. 

 Physiologisch. Studieo ' of Dr. Krukenberg, of Heidelberg. A 

 series of Parts, each containing a variety of memoirs, have been 

 issued by this young physiologist during the past year and its 

 predecessor. It is impossible too strongly to recommend them 

 to the notice of English naturalists, not on account of the im- 

 portance of the results set forth by the author, though^ this is 

 great, but because this Comparative Physiology to which Dr. 

 Krukenberg is devoting himself is, without any possibility of 

 doubt, the path which Biology has to tread m the immediate 

 future. Dr. Krukenberg has trained himself in the methods of 

 the Physiological Laboratory (he is a pupil of Prof. Kuhue); and 

 now he proceeds to apply the graphic methods of record, the che- 

 mical analyses, the toxicological conclusions of the physiologist 

 of frogs and rabbit, to the wider field of zoological material. The 

 colours of birds, of marine animals, the blood of worms and mol- 

 luscs, the movements of the heart of Tunicates, the digestion of 



