The relation between mechanical displacements applied to a cat's pad and the resultant impulse patterns.

1. A way of determining an approximation to the distribution of impulses resulting from certain mechanical stimuli to a cat's pad is described. In essence this consists of calculating the results from a model of the way in which the impulses are set up.2. The results of these calculations have been compared with results of experiments of a type different from those on which the calculations were based. Total numbers of impulses have been found by measuring mass action potential areas under appropriate conditions. The ranges of absolute numbers of impulses are similar for both calculated and direct results. The curves relating changes of number to changes of stimulus strength are similar in the two cases as are the effects of changing the position of the stimulus. Similar comparisons using two pulses at different times and distances apart have also been made. The over-all time distribution has been checked by reconstructing mass action potentials from the calculations and comparing these with those observed.3. The calculations were carried out with values which were chosen in advance and which were based on previous experimental evidence; the results were in reasonable agreement with the experimental checks. It is therefore concluded that the results are a sufficiently good approximation to the neural responses of cats' pads to this type of stimulation to justify applying them in answering the questions posed in the Introduction.