Science: The Dinner Bell

Another brick in the pile of evidence that is gradually being built up by Kammerer, Guyer and others in favor of the theory of ” inheritance of acquired characteristics” (TIME, May 12) has been laid by Professor Ivan P. Pavloff, great Russian physiologist, who visited America last Summer (TIME, July 23). In an address given at the Battle Creek Sanitarium and published in Science last week, he described his latest researches on “conditioned reflexes ” in animals.

Dr. Pavloff’s newest experiments, not yet completed, are on white mice. The rodents were trained to run to their feeding place at the sound of an electric bell. It took 300 repetitions of the feeding-ringing combination to make the mice run at the sound of the bell. The same thing was tried on the offspring of the original mice, and they learned the connection after only 100 repetitions. The third generation absorbed the theory after 30 lessons, the fourth required 10 repetitions and the fifth but five. The sixth generation will be tested after Dr. Pavloff’s return, but he thinks it very probable that after a time a generation of mice will be bred that will run to the feeding place on hearing the tinkle of the bell, with no previous lesson,