ABSTRACT
The late Prof. McDougall’s four ‘Reports on a Lamarckian Experiment’ are likely to become a classic of experimental biology, as being the most sustained attempt up to the present to demonstrate the reality of Lamarckian inheritance in a particular instance. Although, as will appear from this account of our own experiment, we do not believe that it will take its’ place in the history of biology as a successful attempt, we take this opportunity of acknowledging our appreciation of his nearly twenty years’ devotion to this very laborious and exacting experiment.
Strictly speaking, attempted escapes. Occasionally a rat makes contact with the electrified ramp, but instead of climbing it, turns back on receiving the shock, swims to the other exit and escapes by it. This very rarely happens except during the first 4 or 5 days of training. This is recorded as an error.
This must not be interpreted as implying that we accept Crew’s explanation of the decreasing number errors obtained by McDougall.
McDougall, however, does not count it an error when a rat swims up to the bright ramp, touches it with its nose, and on receiving the shock turns away, and swims out by the other passage. He says (1938, p. 329) that if these had been counted as errors (as we have done in our own experiment), then the number of cases of zero error would have been considerably reduced.
