On the side of the telescope opposite to the horizontal axis is attached a graduated circle g, and, turning concentrically with this circle, is a framework h, to which the readers and verniers of the circle are fixed.
It is formed of pavement epithelial cells, mainly grouped in a concentric manner around the vascular papillae of the subcorneous integument, so that a section near the base of the hoof, cut transversely to the long axis of these papillae, shows a number of small circular or oval orifices, with cells arranged concentrically round them.
Most of these cortical bundles are collateral in structure, but in some the xylem and phloem are concentrically arranged; the secondary origin of these bundles from procambium-strands was described by Mettenius in his classical paper of 1860.
All these things were, in their varying degrees, elements of policy upon which the Allied strategy must base itself if its war aims were to be obtained, and accordingly the military treaty between Bulgaria and Serbia provided for a Serbo-Bulgarian army of 7 Serbian and 3 Bulgarian divisions to invade Macedonia, moving concentrically against the front Uskub - Kumanovo - Kratovo - Kochana, forming the outer contour of the plain known as Ovche Polye which was assumed on both sides to be the natural concentration area of the Turks.
A further improvement consisted in passing the metal wire to which the gold leaves were attached through a glass tube much wider than the rod, the latter being fixed concentrically in the glass tube by means of solid shellac melted and run in.