Fio. 1. Roentgenogram showing fracture-dislocation of C~ vertebral body anteriorly on C3 with complete avulsion of neural arch of the axis from the body. (Reprinted through the courtesy of Charles C Thomas and Kahn et al. 5} logical correlation has afforded a plausible concept of the mechanism involved in such fracture-dislocations. T h e victims of judicial hanging are naturally not available for study, but traffic victims with " h a n g m a n ' s fracture" m a y survive and thus permit the

In non-primates the nasal fossa manifests a posterior intrasphenoidal extension, accommodating the hindermost ethmoturbinals and an accompanying series of paranasal ectoturbinal cavities within the interorbital region. Primitive primates (e.g. Tarsius, HapaEe, Saimiri) show phylogenetic loss of these cavities (together with the interorbital region and posterior ethmoturbinals) and the presence of an interorbital septum: a maxillary sinus only is present and the frontal and sphenoid bones are not pneumatized.In some phylogenetically advanced primates (e.g. Lagothrix, Alouatta) trends of cerebral enlargement and resultant separation of the orbits have induced some degree of reappearance of the lost interorbital territory, and an enhanced but variable pattern of paranasal pneumatization, involving the frontal and the sphenoid. Details of this pattern are described for Tarsius, Saimiri, Hapale, Cebus, Lagothrix and Alouatta, distinction being made between homologous and merely analogous paranasal cavities.

No abstract

SYNOPSISThe histology is described, for the first time, of the liver, kidney, and heart muscle of the rare and primitive cetacean Caperea (Nwbalcenu) marginata Gray, 1844. Observations are aho submitted on the hepatic histology of Physeter cutodon, Negaptera novmnglice and Lagenorhynchus cruciger, and a tentative hypothesis is advanced concerning the mode of venous drainage of the cetacean liver lobule. Attention is drawn to a hitherto undescribed histological feature of the kidney of Caperea, Physeter, Plwccenu and Lagenorh,ynchus, and its interpretation is attempted in terms of renal structure and function.

Current osteological literature manifests an unacceptable lack of uniformity in the topographical definition of the mammalian cervical pleurapophysis. Definitions advanced are inadequate or erroneous or even mutually contradictory. A new and corrective definition of the cervical pleurapophysis is therefore propounded satisfactory to the phylogenetic and morphological requirement of vertebral serial homology.