xxvi Journal of Comparative Neurology, 



segments supply the anterior aspect of the hind limb and the 6th-9th 

 the posterior aspect. 



The joints do not correspond to segmental limitations. 



The segmental law rather than functional co-ordination is the 

 basis of distribution. 



Peyer's statement of the correspondence of locality of the mus- 

 cular and cutaneous distributions of a spinal nerve does not apply to 

 the monkey. 



Muscles and Nerves in Mermis and Amphioxus. 



Rhode^ sharply criticises Retzius, and attempts to show that the 

 latter has been mislead by appearances and that the supposed nervous 

 fibrillae which have been described as passing from the motor roots 

 into the cord are not nervous. A hyaloplasm is supposed to exist 

 where it has not been demonstrated. In any event, the supposed 

 nerve fibres are neuroglia or connective tissue and consequently non- 

 conducting. 



The radiating fibres described by Retzius in the cord are simply 

 spongioblasts. 



The Cerebrum of Ornithorhynchus paradoxus. 



Dr. Alex Hill- interestingly describes the cerebrum of the duck- 

 bill platypus. The brain is truly mammalian, but has a remarkable 

 development of the rhinencephalon, hippocampus and the cerebral 

 commissures. 



The olfactory bulb is quite free from the frontal portion of the 

 hemisphere. Its stalk is quite thin and connected with the under sur- 

 face of the hemisphere near the median line. The portion of the 

 mantle which receives it is separated from the general surface by a 

 deep ectorhinal fissure which nearly reaches the mesal surface. The 

 pyriform thus blends with the hippocampal fold. The latter is enor- 

 mously developed and is continued forward to the extreme anterior 

 end of the brain, forming with the rhinencephalon a loop open in 

 front. 



No fibres cross the incisura pallii longitudinalis dorsally to 

 the hippocampus and the callosum is therefore considered to be ab- 

 sent. A strong commissure or decussation lies within the concavity 



'^ Math. ti. naturw. Mittheil. Prcjis. Akad. Berlin, July, 1892. 

 '^ Proc. Roy. Soc, June, 1892. 



