98 DR. BEALE, ON NERVE-FIBRES AND TISSUES. 
same animal, but also in the nerves distributed to similar 
parts in different animals. Besides, the nuclei are found 
more numerously in the nerves at an early period of develop- 
ment than in the fully developed nerves. For instance, the 
nerves distributed to the leg muscles of the frog contain 
fewer nuclei than those which are distributed to the muscles 
of the eye, tongue, or heart of the same animal. Again, 
the nuclei contained in the nerves distributed to the 
thigh muscles are far more numerous in mammalia, espe- 
cially in the mouse, than in the frog. The general conclusion 
which may be drawn from these facts is, that the nuclei con- 
nected with the nerve-fibres at the periphery are the special 
organs upon which depend the growth and multiplication of 
the fibres, and most probably, through their influence, the 
nerves are brought into relation with the different tissues of 
the body. It may be also inferred that, when a tissue is 
supplied with numerous nuclei, its importance as a structure 
or apparatus concerned in nervous action must be very great. 
As Dr. Beale, by a careful examination of a great many 
specimens, has never been able to find an end to the nerve- 
fibres, either at their peripheric distribution or at their im- 
plantation into nervous centres, he is strongly of the opinion 
that the fibres proceeding from a central nerve-cell return to 
the same cell, after a course more or less circuitous and 
tortuous. They may be connected during their course with 
other cells and fibres, but the circuit which they form is 
considered by Dr. Beale to be complete; so that every 
nerve or ganglion-cell with the fibres which proceed from it 
establishes and forms a nervous circuit. This circuit, however, 
is not independent, but always in relation with the circuits 
formed by the other cells. According to this view, it is 
very probable that all nervous phenomena, either of motion 
or sensation, are associated with the setting free of electric 
or of some other current allied to it, and its conduction to 
distant parts above the fibres. Chemical and _ physical 
changes which take place in the germinal matter of the 
nerve or ganglion-cells at the centre or periphery lead to the 
production of the currents. The supposed currents must 
always originate in, and start from, the germinal matter 
alone ;—the nerve-fibres being, as agreed by all observers, 
mere conducting fibres. 
Dr. Beale’s views on the anatomy of nerve-structures and 
organs and their action are opposed to the conclusions of 
most of the German observers. And if their statements 
respecting the existence of a polar or unipolar cells, and the 
free termination of nerves, could have been proved true, Dr. 
