50 ANATOMY. 



directly, as in the two former cases ; or indirectly, by tendons, as 

 in the last. In all instances, however, each fibre, as it ends, breaks 

 up and merges into a bundle of fibrous connective 

 Fig. 26. tissue, either as shown in Fig. 25, e, or by first 



coming down obliquely on a tendon as in /. 

 Usually the individual muscular fibres run along 

 a fasciculus without branching ; but in the tongue, 

 lips, and face, they subdivide before they are lost 

 in the submucous or subcutaneous tissue. 



In the heart, the muscular fibres are striated ; 

 but the tubular sarcolemma is indistinct or absent. 

 Moreover, the fibres themselves subdivide and 

 unite again, so as to form a network ; the bundles 

 Fig. 26. (The Author.) A of fibres also frequently interlace ; and, in some 

 short piece of a compound animals at least, fusiform nucleated fibre-cells have 

 muscular fasciculus show- b amongst them. The heart substance, 



ing, on its cut end, its com- 6 . > 



ponent little bundles, or ui- therefore, shares the characters of both the striped 

 timate fasciculi, slightly and unstnped muscular tissue. Moreover, these 

 magnified. two f orms o f muscular tissue have another trans- 



itional or connecting link between them ; for some- 

 times the unstriped fibres have their granules or sarcous elements 

 arranged in rows as disdiaclasts, thus imperfectly but decidedly ap- 

 proaching the character of the striped fibre. 



The striped or ordinary muscles are exceedingly well supplied with 

 blood, their minute or capillary vessels running between the indi- 

 vidual fibres, and forming elongated meshes, as shown in Fig. 35, a. 

 Lymphatic vessels are absent, or very few. The nerves of the striated 

 muscles are likewise very abundant; they come from the cerebro- 

 spinal system: their mode of termination will be presently adverted 

 to. (See Fig. 30.) The vessels and nerves of the non-striated mus- 

 cles are not quite so numerous; their nerves are derived chiefly from 

 the sympathetic system. 



Nervous tissue. The brain, spinal cord, and nerves consist essen- 

 tially of the gray and white nervous substances which, besides connec- 

 tive tissue and bloodvessels, in which latter the gray substance is very 

 rich, contain three distinct microscopic elements, viz., nerve-cells or 

 ganglionic corpuscles, gray or gelatinous fibres, and white or tubular 

 nerve-fibres. In some situations, growing cells, free nuclei, and gran- 

 ules are found, as, for example, in the cerebellum. 



The ganglionic corpuscles, Fig. 27, are nucleated cells, that is, vesic- 

 ular bodies containing, besides a pulpy matter, an eccentric roundish 

 body or nucleus, inclosing one or more nucleoli, surrounded by col- 

 ored granules. Some of these nerve-cells are rounded, others oval, 

 some pyriform or pear-shaped, others caudate, and some stellate or 

 provided with branched offsets, completely continuous with the cell- 

 wall and the contents of the cell itself. They are found in the gray 

 substances of the cerebrum and cerebellum, as <?, d, e; in the spinal 

 cord, b ; in the knots or ganglia of the sympathetic nerve, a; and at 

 the terminal expansions of the nerves of sight and hearing ; also on 

 the nerve-terminations in glands and perhaps elsewhere. They vary 



