The Genus Phyllospadix 411 



wall between the sacs disappears at the dehiscence of the 

 lobe, after the usual mode in anther-lobes in quadrilocular 

 anthers, and leaves the lobe " i-celled," as the phrase is. 

 But in all the Phyllospadix examined, the dividing cellulose 

 wall, after the discharge of the pollen, is left as a firm mem- 

 brane (Fig. D, a). This gives somewhat greater protection 

 to the pollen, no doubt, than the more fragile wall found in 

 Zostera. 



While at the Hopkins Seaside lyaboratory, I was enabled to 

 investigate the anther dehiscence and the probable mode of 

 pollination. This was done by means of the sea-water tanks, 

 as well as observations along the shores of Monterey Bay. 

 The alternating low-tides on this coast are known as the 

 ' ' large ' ' and "small " . The ' ' large ' ' tides at the change of 

 the moon often leave Phyllospadix uncovered ; but at such 

 times these tides do not occur when the sun is much above the 

 horizon, so there is little chance of leaves or flowers being 

 destroyed, as they would be if exposed to the air and sunlight 

 at the same time. The staminate plants are much less num- 

 erous than the pistillate. In the localities most favorable for 

 the Ph. Torreyi flowers, the proportion of staminate to pistil- 

 late was about one to twelve. In more exposed situations 

 staminate plants were much rarer, and on much exposed 

 shores pistils of Ph. Scouleri* often fail to be fertilized, — per- 

 haps not wholly on account of the scarcity of the staminate 

 plant, for the violence of the surf no doubt disperses and de- 

 stroys the pollen to a greater extent than in quieter places. 

 The staminate plants, according to my experience, occur more 

 inshore ; the pistillate plants are all about them, extending 

 also into deeper water. 



After the anthers with partially reflexed retinacula have 

 been exposed to the air for a time in the low early-morning 

 tide, or have remained in the comparatively quiet shallow 

 slack-water of the ebb, they will open more readily, with the 



* Hooker's erroneous figure showing an ovoid pistil (Flora Bor. 

 Anier. II, t. 186.) may have been based on a specimen with unfertilized 

 withered ovaries. His "capitate stigma" is the tip of astyle from which 

 the stigmas have fallen. * 



