Recent researches have, however, tended to show that Owen was after all right in denying the existence of a corpus callosum in the latter groups. Even allowing for this correction, the result of this important paper was to discredit among all zoologists capable of forming an adequate opinion on the subject Owen’s proposed fourfold division of the Mammalia into Lyencephala, Lissencephala, Gyrencephala, and Archencephala. And these terms have now completely disappeared from zoological literature. In those days it required no considerable amount of courage to attack a man of Owen’s established social and scientific position on an important subject like this; and Flower’s triumph was therefore the more conspicuous. Of course such of these discoveries as are valid, if they had not been made by him, would have been made later on by somebody else, as they merely required accurate dissection and observation. But this may be said of every discovery of a like nature; and Flower is entitled to all credit for having worked out the subject in the way he did. It may be added, that, with our present knowledge of mammalian morphology, a classification based on the characters of the brain is manifestly based on a misconception from first to last; the degree of development and specialisation of that organ being purely adaptive features, and therefore not dependent upon structural relationships. Had Owen’s classification been maintained, it would have been necessary to assign the primitive Carnivora and Ungulata to a group quite apart from the one containing their existing representatives. In the light of modern research, it cannot now be held that the result of Flower’s investigations in this direction was to demonstrate the existence of a corpus callosum to the brain in all the members of the mammalian class. In another paper, dealing with the brain of the Javan loris, published in the _Transactions_ of the Zoological Society, Flower made a further contribution to the study of this part of the organism. Previous to the appearance of the memoir on the marsupial and monotreme brain, Flower had published, in the _Natural History Review_ for 1864, one on the number of cervical vertebræ in the Sirenia (manati and dugong). Apart from several papers on whales and dolphins, which, as already mentioned, are reserved for consideration in a later chapter, the next noteworthy zoological contribution from Flower’s pen appears to be one on the gular pouch of the great bustard, published in the Zoological Society’s _Proceedings_ for 1865. This pouch, which, it may be observed is confined to the cock-bird, and inflated during the breeding season, is a very remarkable structure, which has recently been described in greater detail by Mr. W. P. Pycraft.