312 MICROSCOPIC ANATOMY OF THE ORGANS. 



corpuscle there may be as many as sixty lamellae. Between the 

 lamellae there is a clear serous fluid. Each lamella is lined on 

 its inner surface with flat epithelioid cells lying near one 

 another. The outlines of these can be demonstrated by treat- 

 ment with silver nitrate. Blood capillaries have been found in 

 the lamellated part. These corpuscles are over 2 mm. long and 

 are easily visible to the naked eye. They are found in the 

 connective tissue under the skin of the palms of the hands 

 and soles of the feet, especially in the fingers and toes. They 

 occur also in the joints, the periosteum, in the mesentery and 

 pancreas of the cat, etc. 



(3) Nerve-endings in Muscle. 



(a) Motor Nerve-endings. 



In smooth muscle the nerve-endings have the following 

 arrangement: The nerve fibre enters between the muscle 

 bundles, and, dividing there, passes between the individual 

 muscle cells. The whole fibre shows varicosities throughout 

 its course, and ends freely on the surface of the cell by means 

 of end thickenings. The latter are in direct connection with 

 the cell, although the termination of the fibre never reaches 

 the inside of the cell. It therefore has no connection with 

 the nucleus of the muscle cells, as was claimed formerly. 



In heart muscle the motor nerves end on the surface of the 

 cell in small swellings. In most cases it is probable that each 

 muscle cell possesses a different nerve fibre. By an anasto- 

 mosis of the nerve fibres a terminal network is formed, from 

 which the final end fibres proceed to the muscle cells. 



In striated skeletal muscle bundles of medullated nerve 

 fibres form networks in the perimysium. Terminal fibres 

 proceed from these networks to the individual muscle fibres, 

 on whose surface they end (Fig. 236). The sheath of Schwann, 

 as well as that of Henle, ceases before it reaches the muscle 

 fibre. According to some authors, however, these two sheaths 

 fuse with the sarcolemrna. The medullary sheath ends where 



