At the meeting of German neurologists and alienist physicians in Baden-Baden, June, 1901, Dr. Bethe, of Strasburg, explained that during the last decade a new nerve-cell theory had come into vogue. It was assumed that the so-called neuron was an anatomical, functional, pathological, and developmental entity. But it had been shown by Apáthy that there is a direct and intimate connection between the neurons through the primitive nerve-fibrillæ, and Dr. Bethe himself had demonstrated that in the carcinas mænas the nervous system performs its function without any ganglion cells. Thus the cell cannot be a necessary instrument in the process like the pendulum of a clock, or the wheel of a watch. Nissl has shown that the observations of pathologists give no sure support to the neuron theory. Further objections may be taken from the fact that several organs are affected after section of the nerves supplying them. In the case of degeneration of muscles and glands, it may be said that this process may be owing to atrophy from inactivity of their functions; but degeneration of the papillæ circumvallatæ et foliatæ of the tongue in the rabbit has been observed to follow, in from about two to three weeks after section of the glossopharyngeals, although the stimulus has not ceased to be applied to these organs. From this it appears that the pathological process goes further than the boundary of the neuron.

The work, which has led to the production of this excellent monograph, has occupied the author for three years. It has finally been brought to a conclusion at Claybury, and is one of the best pieces of work which has yet hailed from that laboratory. Dr. Bolton has bestowed an enormous amount of industry and care upon his work, and it is a difficult task to do justice to it in an epitome.

The first lecture dealt with the general composition of nervous structures. Grey matter contains 80—90 per cent. of water, and 50 per cent. of the total solids are proteid. In white matter there is less water and less proteid, and in peripheral nerves is least water and least proteid. The most abundant proteid is a nucleo-proteid containing ·5 per cent. of phosphorus, but there is little of this in the white matter. The other two proteids are globulins, one of which coagulates at 47° C.

This is an anatomical study of two heads by the sectional method, special attention being directed to the exact position of the lateral ventricles. The author is one of the New York medical students.

Lecture I.—After a brief historical summary of the growth and conception of the neuron theory, the lecturer prefaces his observations upon degeneration of the neuron with a short account of the minute histology of the nervous system as revealed by modern methods.