TY  - JOUR
T1  - THe elementary nervous system.
Y1  - 1919/08/30
N1  - 10.1001/jama.1919.02610350060030
JO  - Journal of the American Medical Association
SP  - 712
EP  - 712
VL  - 73
IS  - 9
N2  - This volume, the second of a series of monographs on experimental biology by American investigators, includes an "extended discussion of only the simplest examples of the elementary nervous system" as Parker himself states in the opening sentence of the last chapter. The author shows that contractile tissue (as effectors in the form of muscle cells) appears before any form of nervous tissue. Subsequently, there is added a receptor or modified epithelial cell which influences the effector more quickly because it is more sensitive to the external stimuli (chiefly physical) which originally acted on the effector organ directly. It is a "trigger, so to speak, to discharge the underlying muscle, and judging from the quickness with which this discharge is accomplished as compared with that with which the independent effectors discharge, the efficiency of the new system is beyond doubt." To this receptor-effector system is added later on a third type
SN  - 0002-9955
M3  - doi: 10.1001/jama.1919.02610350060030
UR  - http://dx.doi.org/10.1001/jama.1919.02610350060030
ER  -