president's address. 687 



putting Noloryctes clown as an Edentate. He gives the following 

 as the complete dental formula: — i. f, c. J-, pm. |, m. | = t§. 



As a result of comparison with the various families of Marsupials 

 he arrives at the conclusion that the Notoryctidae are a family of 

 Polyprotodont Marsupials more nearly related to the Dasyuridae 

 than to the Feramelidae. 



In Owen's memoir " On the structure of the Brain in Marsupial 

 Animals," published in 1837, he states that the marsupial brain 

 is devoid of the corpus callosum or great commissural band 

 between the two cerebral hemispheres so liighly developed in the 

 placental mammals. The study of the brains of the Platypus and 

 Echidna by Eydoux and Laurent, and later by Owen, led to a 

 similar result with regard to the Monotremes. These statements 

 were uncontroverted, and accordingly became incorporated in all 

 the text-books of comparative anatomy, until in 1865, Flower 

 published a paper in which he maintained that a true corpus, 

 callosum is present in the Marsupials and the Monotremes, though 

 in a rudimentary form. Last year Johnson Symiugton read a 

 paper on this subject before Section D of the British Association* 

 in which he shows that what was regarded by Flower as repre- 

 senting the corpus callosum in the brains of Marsupials and 

 Monotremes, is, as shown by the distribution of its fibres, in reality 

 a commissure connecting the hippocampi majores and gyri dentati. 

 So that, as Flowerf has himself acknowledged the correctness of 

 this view, we come back to Owen's original opinion that a corpus 

 callosum does not exist as such either in the Marsupials or the 

 Monotremes. 



Sir "William TurnerJ has investigated the external anatomy of 

 the brain of Oriiitliorhynclms. A comparison with that of Echidna 

 shows that the latter possesses a higher organisation ; its bulk, 

 as is well known, is much greater, its cerebral convolutions more 



* " The Cerebral Commissures ia the Marsupialia and Monotremata." 

 Journal of Anat. and Phys. Vol. XXVII. (1892). 



t Report of a meeting held in connection with a proposed memorial to 

 Sir Richard Owen. " Nature," 1892. 



X Journal of Anatomy and Physiology, XXV^I. (1892). 



