=========+==========+=========+=========+==========+========== MARTIAN | DECEMBER | JANUARY | JANUARY | FEBRUARY | FEBRUARY DATE, | (16) | (1) | (17) | (5) | (24) ---------+----------+---------+---------+----------+---------- | % | % | % | % | % Northern | 50 | 50 | 0 | 25 | 50 Southern | 50 | 50 | 0 | 0 | 25 =========+==========+=========+=========+==========+========== From this table we may place the lowest point of the blue-green tint as reached about the 22d of January for the northern, the 5th of February for the southern, part. This would indicate that the wave of returning growth came from the north, not the south; an important fact, as we shall see later in studying the action of the canals. [Illustration: Mare Erythræum Martian date. February 1] At the next opposition, in 1905, a recurrence of the transformation was watched for, and not in vain. It occurred, however, somewhat later in the Martian season. On December 27 of the planet’s current year the Mare Erythraeum was still as usual, blue-green, nothing out of the ordinary being remarked in it; and so it was on its January 17, although the southern edge was darker than the northern. It looked certainly as if the metamorphosis were this year to be omitted. But such was not the case. When the region again came round, on February 1 of the Martian calendar, there the strange tint was as unmistakable as it had been on its original occurrence. Not only was the Mare Erythraeum so colored, but on February 5 (Martian) the northern portion of the Mare Cimmerium was observed to be similarly affected. In the Mare Erythraeum the anomalous chocolate hue was confined to a belt between the latitudes of 10° and 20° south of the equator; in the Mare Cimmerium it stretched a little higher, from 10° at the west to 25° at the east. It is noteworthy that the southern portion of the latter showed blue at the time the northern showed brown. Then the metamorphosis proceeded as shown in the following table:— MARE ERYTHRAEUM 1905