The descending projections of the archistriatum towards the pons and medullar oblongata were investigated in male, younger chicken by using iontophoretically the cholera toxin Bchain conjugated to horseradish peroxidase(CTBHRP) into the archistriatum.

The precise termination areas of the descending projection from the medullary subnucleus reticularis dorsalis (SRD) to spinal gray matter in the rat were investigated by injection of an anterograde tracer, phaseol us vulgaris leucoagglu tinin (PHA-L) into the SRD.

In addition, the construction of the basic behavior element supporting the behavior reflection is explained in detail and two typical examples ar.