This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1915 Excerpt: ... necessary to conclude that generally, if not always, the result of cutting a Macrocystis plant is to bring about a gradual decay of the particular stipe from the region of the cut back toward the-holdfast, and that the regeneration of a cut bed is mainly, if not entirely, from the growth of new stipes, starting at or near the holdfast. The rate of growth is very difficult to ascertain, but beds at La Jolla and Encinitas, which were practically washed away by the storm of March 9 and 10,1912, are rapidly being replaced by new beds. Possibly from one to two years" time will be needed for the bed to regain its former thickness. A similar condition was noticed by Dr. Eitter, of La Jolla, some years ago, and then it took about two years for the bed to recuperate. In these cases the plants were destroyed and new plants had to develop from the bottom. These new plants were probably started from spores from the few plants remaining. The rate of growth shown in these cases would not be the same as in the case of cutting off the tops; the latter would probably give a much faster rate of growth. From observations made at San Pedro the rate of growth must be very rapid in topped plants. This problem is now being studied at San Pedro. Quite a number of measurements were made of the depth at which Macrocystis grows in typical beds. The inner or shore side of these beds varied in depth from 1 to 3£ fathoms, but averaged close to 2£ fathoms, while the outer or seaward edge varied in depth usually from 4 to 7 fathoms, averaging 5f fathoms. Generally, in northern waters, the Macrocystis was found at shallower depths, but plants were occasionally found at quite as great depths as in southern waters. POTASH AVAILABLE FROM KELP. In the survey of the kelp beds from Sa...