146 THE SALTON SEA. 



of the slopes of the Sink, although the observations on this matter have not been made 

 with the exactness with which the matter was treated with regard to A. canescens and 

 Parosela emoryi. 



A lot of seeds were cast into a vessel of Salton water on February 13, 1913, with 

 the result that all floated for a few days, then began to sink, so that nearly all were on 

 the bottom in three weeks. No germination ensued. The failure of the seeds to germi- 

 nate may be ascribed to their age, and no opportunity was obtained for making a test with 

 fresh seeds. 



Airiplex lentiformis is a shrub which attains huge dimensions, the larger individuals 

 making a dome-shaped mass which may be 15 to 25 feet high with a diameter nearly as 

 great. The flattened utricles weigh 7 or 8 mg. and mature in the autumn. A supply was 

 collected by Mr. S. B. Parish in October 1912 and 100 of these in an air-dried condition 

 were thrown into a vessel of Salton water on November 16, 1912. These seeds showed a 

 marked partial buoyancy. Nine sank on the second day after shaking, but the greater 

 number remained afloat and germination ensued in both lots within a week. The radicles 

 elongated so rapidly that a length of 1.5 to 2 cm. was reached within a week, and the 

 plantlets remained in indefinite positions in the water, some resting on the bottom at a 

 depth of 10 cm., others midway, others floating on the surface, all changing position to 

 some extent with illumination and temperature variations (see Plate 27). The total 

 number of germinations amounted to 85, and with warmer weather all of the plantlets 

 rose to the surface, where they were noted on January 10, 1913. Lots of these were placed 

 in the shallow water covering loam in a glass dish, but none of them struck root and sur- 

 vived the "stranding," although it is possible they might have done so if they had been 

 tested as to this matter earlier; some attenuation and weakening had already been mani- 

 fested when the trials were made. 



This species is abundant in the Mecca region and the seeds might readily be carried 

 down the beach slopes by run-off streams, birds, or other agencies. The introduction of 

 the plant on the Travertine Terrace and on Obsidian Island, however, might have been 

 due to birds or to the flotation of seedlings or to seeds, although the distance to be bridged 

 renders the last-named method the least probable of the three. Among these introductions 

 is the notable instance of a single individual on Cormorant Island, in 1912, its only known 

 introduction to this place in five years. An occurrence of no less interest was that noted 

 in October 1912, when some plants were seen on the emersed archipelago near Big Island. 

 Flotation of seedlings or transportation of seeds by birds is suggested in the last-named 

 instance (Plate 23 a). 



Baccharis glutinosa is a woody composite (reaching a height of 2 meters or more, with 

 lanceolate glutinous leaves) which blooms all through the summer, and the compressed 

 ribbed fruits, with a long silky pappus, become free from the receptacles in November 

 and December and are supposedly carried about by the winter winds, many of course 

 falling on the water. It proved difficult to free the fruits from chaff for weighing, and 

 although they were seen to be not the lightest seeds tested, yet the surfaces offered by the 

 pappus caused them to be carried long distances by air-currents; 100 of the fruits taken 

 from an herbarium specimen collected in November 1908 were thrown into Salton water 

 November 16, 1912, and floated without being wetted for some time. Shaking caused 

 two to sink to a slight depth on the following day, and these had descended to the bottom 

 on the 26th; five were down on December 9; eight were at the bottom on December 14, 

 and no further changes were noted except that mould had formed on the floating fruits. 

 This state of affairs prevailed as late as January 20, 1913. Shaking did not sink any more 

 of the fruits, which were found to be nearly ail imperfect; 35 which had sunk seemed to 

 be soimd. No germinations having ensued by March 9, or 115 days after the seeds had 

 been put into the water, the preparation was discarded, as at this time the seeds had 



