Literary Notices. clxxv 



The Cerebriiin of Ornithorliynclius.^ 



Although containing, as the author modestly puts it, ''little more 

 than a series of detached observations," these are a welcome addition 

 to the meagre literature of this subject. 



The olfactory bulb seems to be as in Didelphys, though Hill says 

 it differs, without specifying how, in the relations of the fossa. So 

 far from being an exceptional thing, the olfactory fossa is found gen- 

 erally in reptiles, having been described by the writer in Alligator and 

 many other types ; it is less pronounced but obvious in many rodents. 

 Generally the cavity is filled with glomerulary aggregates. The ven- 

 tricle is obliterated in Ornithorhynchus. The external form of the 

 brain has been described by Sir W. Turner.- 



A considerable portion of the paper is devoted to an historical 

 discussion of the callosum, which is said, on anatomical and morpho- 

 logical grounds, to be absent. Elsewhere in this number reference is 

 made to the same organ as seen in the oppossum. The method of 

 preservation was evidently such as to prevent determining fine histol- 

 ogy. The figures, being for the most part quite devoid of reference 

 letters, make it difficult to follow the discussion in some cases. From 

 the figures it would be inferred that the fascia dentata is quite disasso- 

 ciated from the cornu ammonis and we are reminded that the author 

 does not accept the former as a convolution. There is the greatest 

 simplicity in the arrangement of the fimbria and fornix. 



Descriptions are given of the central gray matter and cortex, for 

 which see the original. 



The descending pillars of the fornix are said to divide into two 

 bundles, one of which extends along the upper surface of the thala- 

 mus (taenia ?) while the other descends to the large corpus mammil- 

 lare. We trust that Dr. Hill may not be disappointed in his hope to 

 be able to secure well-preserved material for future study. 



The Hippocampus.^ 



In this monograph. Dr. Hill gives an interesting summary of the 

 history of this much-discussed organ. He denies, though without 

 presenting evidence, that the lateral striae of the olfactory reach the 

 surface of the region in lamina nuclearis and fascia dentata and also 



iHiLL, Alex. The Cerebrum of Ornithorhynchus paradoxus. Fhilos, 

 Trans. Rdy. Soc, London. Vol. 184 B, p. 367-387. 



'^Jonrn. Anat. Phys. XXVII, April, 1892. 



^HiLL, Alex. Philos. Trans. Roy. Soc. London. 184. 



