DR. JOHS. SCHMIDT'S happy intuition as to the choice of successful investigations is again exemplified by his latest memoir. Here he has examined samples of cod from all over its north Atlantic region of distribution. In each fish (about 20,000 in all) the numbers of vertebrae and the numbers of rays in the second dorsal fin have been counted. The results are fully displayed in a series of tables and charts. They are very remarkable and unexpected.