DR. BEALEj ON THE TISSUES. 85 



fibres which will grow from the original bundle. In propor- 

 tion as these branches increase^ the trunk and the ganglion, 

 or ganglia connected with it, Avill increase. The nuclei of 

 these fibres, like those of all nerves near their distribution, 

 undergo division and subdivision, and thus new fibres are 

 formed according to the requirements of the part. A small 

 band of gray fibres cannot be separated into individual fibres, 

 nor can you divide the terminal branches of a cerebro- spinal 

 nerve into distinct and separate fibres. Many of the finest 

 fibres exhibit an indication of being composed of two or more, 

 and this division seems to be continually going on in the 

 peripheral branches of all nerves, and occurs in the trunks of 

 the sympathetic system. 



Voluntary muscle. — Connective tissue exists between the 

 elementary muscular fibres of the voluntary muscle of man 

 and animals, and it has been considered as a constant struc- 

 ture, and subservient to certain important purposes, in this 

 situation. The proportion of this connective tissue varies 

 greatly in the voluntary muscles of different animals, and in 

 those of the same animal at different ages. During the early 

 period of development of muscle this connective tissue is not 

 observable, and in the muscles of small animals, such as the 

 mouse, only traces are to be demonstrated. The elementary 

 fibres of the muscles of the young mouse seem to be quite 

 destitute of connective tissue. On the surfaces of the ele- 

 mentary fibres of all voluntary muscles, at all periods of life, 

 are a number of oval corpuscles or nuclei, and these are 

 found in eases where very much connective tissue is observed, 

 and also when no traces of this structure can be found. They 

 are generally considered to be nuclei of the areolar or con- 

 nective tissue, and are the bodies regarded as " connective 

 tissue corpuscles." 



A preparation showing the muscular fibres of the dia- 

 phragm of a young white mouse with their nerves, capillaries, 

 and the numerous nuclei connected with them, was passed 

 round. The preparation is destitute of connective tissue, and 

 all the corpuscles are connected with the capillaries, which 

 are injected, with the nerve fibres, or with the muscular 

 tissue itself. 



General remarks on areolar tissue. — A certain form of con- 

 nective tissue not unfrequently results from the imperfect 

 development of elementary parts from which a much higher 

 tissue might have been produced. This was illustrated in the 

 following preparation, in which some of the bundles of mus- 

 cular fibre cells at the edge of the uterus of the mouse were 

 seen. Those situated most externally were observed to differ 



