The large dark stained cells are neurons.  The smaller lighter stained cells are neuroglia.

A single neuron.  A = axon.

A single neuron using a different staining technique.  B = boutons (axon terminals) making synapses with the neuron soma. 

Nervous tissue.  Purple bodies are the nuclei of supporting cells (neuroglia). 

Purkinje cell (a type of neuron) of the cerebral cortex. D = dendrites, A = axon 

A close of axons laid side by side.  Schwann cells surround the axons to create insulation; this aids saltatory conduction.  R = node of Ranvier