8 Transactions of the 



connective tissue. This was more fully formed, largely-granular, in- 

 different tissue. This part was underlaid by the palatal skin, or so- 

 called mucous membrane, with its sub-mucous stroma. But very 

 much of this solid tract had become bony ; and this bone, the para- 

 sphenoid, it is which is seen as bony style, bifurcate behind, in the 

 basal view (Fig. 2, pa. s). Various parts of this bar being brought 

 under the quarter-inch lens, with the low eye-piece, I obtained such 

 views as are given in Figs. 8 and 9. At the fore-part of the bony 

 style (Fig. 8) the trabeculse (tr.) and their common crest were already 

 composed of solid, clear, true cartilage ; here the intercellular spaces 

 were of nearly the same width as the cells themselves, which were 

 proliferating rapidly. Below the convex edge of this truly cartila- 

 ginous plate the tissue was gelatinous — " bioplasm," with inter- 

 spersed granules (g. t.). Below this gelatinous stratum there is a 

 very thick cushion of a very solid granular substance (gr. I.) running 

 under the whole of the ethmoidal and sphenoidal regions. This is 

 peculiarly the case in " Ganoid " and " Teleostean " Fishes, in the 

 Dipnoi (Lepidosiren), and in all the Amphibia and the Serpents, 

 but not in the Cartilaginous Fishes — Sharks, Rays,and Lampreys, nor 

 in Lizards, Turtles, Crocodiles, and Mammalia. In front (Fig. 8) the 

 granules form a thicker stratum, where the bony layer is thinning- 

 out, than behind (Fig. 9) ; farther back it forms a large, outspread, 

 thick mat, in shape like the double leaf of a Banhinia (see Fowl's 

 Skull, Plate 82, Fig. 2, h. t.). In the hinder region (Fig. 9) the 

 gelatinous layer (g. I.) is much thinned-out, and dies away in the 

 solid pras-basi-sphenoidal region (Fig. 7). 



The granules of the granular layer are only half the size of those 

 in the cartilage, and are closely packed, the appearance of inter- 

 cellular substance being due to the bioplasmic jelly in the inter- 

 spaces of rather closely-packed ovoids. I have studied this part of 

 Vertebrate Histology with painstaking care for many years, as it is 

 at first undistinguishable from tracts that soon afterwards become 

 hyaline cartilage. I have examined, with my friend Mr. Chas. 

 Stewart, this substance in the early embryo of the Pig, and when it 

 forms the nidus for the vomer of that animal. In very fine sections, 

 stained with carmine, it has about half the transparency of the true, 

 but very young cartilage of the " prse-sphenoid " and " ethmoid " 

 above it. This is in embryos less than an inch and a half in length. 

 But in piglets double that length it has been metamorphosed into 

 solid bone, and no part of it, then unossified, shows any proper car- 

 tilaginous character. Yet in those earlier embryos it had a very 

 much greater transparency than the surrounding mother-tissue, 

 which was ready to become connective fibre. 



This tissue has been called " simple cartilage," and still better, 

 by Professor Huxley, " indifferent tissue," as it seems ready to be 

 by metamorphosis for any duty that may be imposed upon it. These 



