744 
MR. A. SANDERS ON THE ANATOMY OE THE 
consist of a central core of granular material, which in fortunate preparations is seen 
to be composed of closely intertwined fibrillse of very fine dimensions; externally 
fibrils of a larger size are to be observed running parallel to the long axis of the 
glomerulus, in the course of which elongated cells are developed. These fibrils 
occupy the outside of and the space between the glomeruli; they converge towards 
the outer or anterior end of these bodies, and go to form a flat bundle of fibrils emerg¬ 
ing from that end of the glomerulus ; at the inner extremity a fibrillar network, a 
continuation of the central core, connects these structures with the internal or third 
layer. 
The course of the fibrillse would seem to be from the cells occupying the internal 
layer into the centre of the glomeruli, where they form a much closer network ; then 
by some means not quite apparent they would seem to join the fibrils, enveloping the 
exterior surface of those bodies to form the bundles which pass out to join the nerves 
which supply the Schneiderian membrane. 
In Scyllium the cells which occur in the course of the external fibrils of the 
glomeruli are rather larger than in the other species, and the cells of the internal layer 
which are found in the neighbourhood of the glomeruli are larger (18g by 14g) than 
those in the interior of the internal layer, which is not the case in the other species. 
With this exception the above account applies equally to all the species investigated. 
The ventricle of this lobe is lined by an endothelium, consisting of a single layer of 
cells; this is a continuation forward of the layer which lines the other ventricles of 
the brain and the central canal of the spinal cord. 
The structure of the peduncle gradually merges into that of the cerebrum without 
any distinct or obvious line of demarcation ; neither are there to be seen any bundles 
of fibres or any crura connecting the one with the other. 
Cerebrum. 
On examining a transverse section through the cerebrum of Ehina, it will be 
observed that externally beneath the pia mater the cerebral parenchyma is composed 
almost entirely of a granular neuroglia, through which a few small cells are sparsely 
dispersed; these measure generally from 7/x to 8/x in length and from 5/x to 7/x in 
width; they give off processes which join the network of fibrillse which pervades the 
neuroglia. This layer occupies about one-sixth of the whole thickness of the cerebrum 
between the external surface and the lateral ventricle. Many capillaries penetrate 
the brain from the pia mater through this part. 
Internal to this layer the whole extent of the remaining five-sixths of the cerebral 
wall is occupied by a mass of cells ; these, in addition to cells more or less spherical or 
oval, resembling those in the outer layer in size and appearance, consist of a great 
number of larger cells, measuring from 10/x to 12p in diameter, together with others 
more or less oval in shape and measuring from 13p. to 8/x in long diameter and from 
