1877.] 



Bodies of the Horse and Dog. 



501 



well-marked in the foetal state of the organ in other mammals. In 

 opposition, therefore, to the usual subdivision of parts, it is proposed to 

 limit the term " cortex to the extreme outer zone consisting of the 

 peculiar structures above-mentioned, and to apply the term " medulla" 

 to the general mass or parenchyma of the organ which the outer zone 

 covers, including in the medulla the extreme central and generally pig- 

 mented part to which the term " medulles " has been hitherto limited. 

 This proposed rearrangement of terms is based upon the fact that the 

 outer zone has no continuity of structure with the zones next to it ; 

 whereas the extreme central part differs from the neighbouring paren- 

 chyma in unessential particulars, and chiefly in the character of the 

 blood-vessels or blood-spaces within it. 



The comparison with structures in the ovary is based upon the above 

 radical distinction of cortex and general parenchyma in the suprarenals, 

 and is worked out in two sections dealing with the two parts respec- 

 tively. The structures in the ovary to which the cortical follicles are 

 compared are here described for the first time, and the discovery of 

 them, and of their nature, has been the starting-point of the present 

 investigation. They are the remains of Graafian follicles within which 

 the ovum, after reaching a degree of ripeness, has shrivelled up and 

 disappeared. The appearances in question are numerous in the ovaries 

 of the bitch, especially towards old age. Their structure is perfectly 

 definite and their occurrence tolerably uniform. They are spoken of as 

 obsolete Graafian follicles, and are to be carefully distinguished from 

 those Graafian follicles from which a ripe ovum has been successfully 

 discharged. 



The ovarian structures to which the general parenchymatous mass of 

 the suprarenal is compared are persistent corpora lutea, entirely solid 

 and cellular. This part of the comparison occupies the second section 

 of the paper, and the details of it are referred to at the end of the 

 abstract. 



Coming to the details of his comparison, the author first states the 

 facts relating to the cortical suprarenal structures. Their form, espe- 

 cially in the horse, appears different in the surface section and in the 

 perpendicular section. But, premising that the same differences of 

 shape occur among the corresponding appearances in the ovary, they 

 may be taken to be essentially elongated closed cylinders, straight, or 

 curved, or tortuous, or doubled up. The cylinders are completely filled 

 with long and narrow epithelial-like cells arranged in close order across 

 their lumen, i. e. at right angles to their long axis. Each cell stretches 

 across, generally speaking, the whole width of the cylindrical space; 

 the nucleus of a cell is generally towards one end, and the other end 

 is often pointed. Cells appear alternately to arise from opposite sides of 

 the space, their pointed or relatively free extremities interlocking among 

 the nuclear or basal ends of the cells opposite. 



vol. xxvi. 2n 



