422 Prof. G. Retzius. Principles of the [June 15, 
Fie. 4.—Nerves of Lumbricus, stained with the aid of the Golgi method. 1. A portion of 
a transverse section, with the skin and the cells of Lenhossék, with their central 
processes running to a ganglion. 2,3, and 4. Transverse sections of ganglia, with 
nerve-cells and their processes, and also with some central fibres of the cells of 
Lenhossék. 5. A little portion of the skin, with the cells of Lenhossék. 6, 7, and 8. 
Endings of nerve-fibres on muscles. 
vertebrate animals was concerned. Of Cajal’s works there may here be cited in 
the first place those dealing with the spinal cord, the cortex of cerebrum and 
cerebellum, and several of the interior cerebral ganglia, the retina, the 
olfactory organ, and the peripheral ganglia (the sympathetic and spinal 
ganglia). In all these organs Cajal not only made important discoveries of 
