ABSTRACT
The mechanism of transport in the axon for anterograde transport materials is not as yet definitively established but it is recognized to be a local process within the nerve fiber, one which requires a supply of ATP and, in many nerves at least, depends on calcium. G. H. Parker's view was indeed very much in line with our modern one of transport, but he could not say what the nature of the materials transported might be. R. W. Gerard summarizing the evidence that the nerve impulse depends on oxidative metabolism, proposed that the enzymes necessary to maintain the metabolism of the fibers were being continually transported down within the nerve fibers from their source in the nerve cell bodies. The concept of a nerve fluid had been given substantiation by the early microscopic studies of Van Leeuwenhoek as described in a letter written in 1717.
