BOOKS AND CURRENT LITERATURE 49 



of fairly even sunshine and the wafer temperatures were not liable to 

 great fluctuation the inference seems safe that the more rapid growth 

 on wind}' days was prol)ably due to the better aeration of the water 

 when disturbed by air currents. 



A second paper^ dealing with this big kelp takes up the rate of 

 growth of stipe of Nereocystis. Some difficulty was experienced in 

 finding a satisfactory method of measurement. The plan finally 

 adopted after preliminary study was to take healthy plants freshly 

 pulled from their natural anchorage and to attach these to the lower 

 portion of a raft which in turn was moored in the margin of a vigorous 

 kelp b(Hl. A fortunate control was found in plants, which, on being 

 pulled from their original place of growth, brought their anchorage 

 rocks up with them. These could then be returned to normal condi- 

 tions each time after measurement thus giving a control on the other 

 measurements. The two sets of plants were found to agree in theii" 

 rate of growth. Fourteen plants under observation for periods vary- 

 ing from two to twenty days displayed a rate of growth in the stipe 

 ranging from j inch to 2| inches per da}' — averaging about 1 inch per 

 day. An old plant which had survived the previous winter had a 

 stipe over 47 feet in length and showed no further growth. Further 

 study showed that the region of elongation in the stipe is not so sharply 

 localized as in the fronds but involves the whole region from bulb to 

 holdfast. The region of greatest growth, however, is the lower hol- 

 low portion of the stipe, which lengthens much faster than either end 

 of the stem. Cut stipes usualty die, apparenth' from the action of 

 organisms at the cut surface or in the interior of the central cavity. 



Another paper- of the series outlines the results of a set of experi- 

 ments to determine the ability of sea weeds to withstand desiccation. 

 These studies continued for a month, and the proof of death from de- 

 siccation was the inability of the plant to resume growth when brought 

 again to favorable relation on the shore. Thirteen species were studied, 

 ranging in habitat from high on the rocks to well toward the low tide 

 line. The results showed that the ability of the these algae to with- 

 stand desiccation agrees with their relative position above the low tide 

 mark and consequent period of exposure between tides. The experi- 

 ments were conducted upon one green alga, five brown algae, and 

 seven red algae. Fucus evanescejis, Gloiopeltis furcata, and Gigartina 



- Sheldon, Sarah M., Notes on the growth of the stipe of Nereocystis luetkeana. 

 Pub. Puget Sd. Marine Sta. 1: 15-lS. January, 1915. 



^- Muenschner, Walter L. C, Ability of sea weeds to withstand desiccation. 

 Pub. Puget Sd. Marine Sta. 1: 19-23. February, 1915. 



