No ODC can bring about a great reform, unless in a social medium already somewhat prepared for it. It was Rolleston's good for- tune to work at & time when liis efforts were not mere hopeless asBaults on a foitrcss ren- dered impregnable by prejudice. He battled at an epoch when many sympathized with him, and were ready to help. But it is his glory to have been the leader, exceptionally fitted by natural gifts and academic career, to conduct to victory those who desired to widen the range of Oxford studies. To him, more than to any other one man, is it due liiat in bio- Ic^cal teachiQg the unirersity on the Isis is now pressing close on the heels of her sister on the Cam.
��Of late years Professor Marsh has been fol- lowing the plan of selecting a certain group of extinct vertebrates, and thoroughly elucidat- ing its structure in an exhaustive monograph. Where practicable, this plan is by far the most aatisfactorj- method of dealing with the subject ; but it seldom falls to the lot of a paleontologist to obtain his materials in the necessary abun- dance. The volume before us ia a magnificent one, surpassing in many respects all other pale- ontological works. Never before has such a remarkably perfect series of mammalian fossils, illustrating a single group, been brought to- gether. Only in the tertiary lake-deposits of western America could such a collection have been formed ; but few can realize what an expenditure of time, labor, skill, and money, even under the most favorable circumstances, is represented by the raw material of this work. Had Professor Marsh done nothing beyond col- lecting, be would still be entitled to the lasting gratitude of all biologists.
Tbe introduction gives a short l>ut sufficient account of the geology of south-western Wyo- ming, the only region where remains of the Dinocerata have been found. The section il- lustrating this part is o|>en to serious criticism, in that it substitutes for the long- established names of formations given by Hayden, King, and Powell, new terms derived from some char- acteristic fossil. Such arbitrary changing of accepted names can only result in ' confusion worse confounded.' This section refers the Laramie to the cretaceous, whereas it is almost certainly tertiary. The Pucrco is altogether omitted.
r*! DiKBcrrala ; a nionngraph e/ an rrllnrl order af gloan- tic maiHiaal: By Othhiel Cu^rles Dibbb. U. S. gvoTogl- nl mrvtj. Uonotr. Vol. i. H'aiAfngton. IKSt. 331 p., U pi.
��The descriptive part of the book opens with a chapter on the skull, in which the most curi- ous part of these most curious animals is ilios- trated with much care. A remarkable aud novel feature of this chapter is the aeries of sections of the skull which it presents. These sections are made in all directions, — trans- verse, vertical, aud horizontal, — and thorough- ly display the internal structure of the skull, the sinuses, cranial cavity, olfactory chambers, as well as the characters of those bones wbich cannot be seen fVom the surface. Professor Marsh has here indicated a new method of investigation, which is certain to \-ield %'aluable results in the future, as !t already has in his hands. Strange to say, the description of the skull ignores almost entirely the basi- occipital, sphenoidal, and periotic regions, as well as the foramina at the base of the cranium. These are most important features, and their omiasioD detracts materially from the value of the (du^»- ter. The lower jaw receives very thorongh description and illustration : its chief peculiar- ities are the backward projecting condyles, and. in the males, the anterior flanges, for the protection of thegreat uppertusks. Professor Marsh shows that in the females these tusks were very small, and that in consequence the flanges of the mandible are absent or rudimeifc^ tary ; thus correcting the very natural error in) which Speir and Osborn had fallen in ing the flange as a generic instead of a soxaa^ character.
The chapter on the teeth need not detain i except to notice the lower incisors and caninee Osborn and Speir first showed that these teeth differed from those of all other ungulates in having bilohed crowns. In his restoration of ■ Tinoceras ' and elsewhere. Professor Marah represents these teeth as having a very diffier- ent shape, though the only actual specimen he figures (woodcut 38, p. 37) is an evidently much-worn canine; of " Dinoceras,' he gives figures of three isolated incisors. We mast believe that the restoration of these teeth in 'Tinoceras' is erroneous.
Certainly one of the most striking and valu- able chapters in the book is that on the brain. The brain in the Dinocerata " was proportion- ately smaller than in any other known mammal, recent or fossil, and even less than in some re^ tiles. It was indeed the most reptilian bra in any known mammal." This is a most i markable and unexpected fact. This cbspte is enriched by an extended and valuable s of cranial casts of mammals from nearly aU tl tertiary formations. Lartet first pointed ( the comparatively small size of the brain Id U
�� �
