148 University of California Publications. [botany 



equatorial l)aiid (Cf. Fig. 6, PI. 15). The protoplasm of the 

 si)ore with the refractive bodies flows into the germinating tube, 

 which grows very long after a few days, branches and becomes 

 septate. After germinating the spores are 10-12 /^ wide and 

 18 /A long. The young mj-celium is 3-4 fj- in diameter when 

 10-100 /^ long. After the spore has been germinated several 

 days, the mycelium begins to branch, and often forms either at 

 the tip or back of the tip bulb-like swellings nearly as large as 

 the spore itself. All along the mj-celium the transverse septa 

 occur at frequent intervals and are very distinct. 



The Ulva-composite grows just about the upper tide mark on 

 the shady side of the sandstone boulders at the entrance of the 

 Bay of San Francisco. It was first collected at Lauds End by 

 Prof. W. A. Setchell in October, 1898. It has since been collected 

 at Fort Point, and probably occurs all along that shore from 

 Lands End to the Fort. It always seeks the shade and some 

 protection from the full force of the waves, and occurs in patches 

 of various sizes from a few inches to several square feet in extent. 

 It has been collected every month in the year and always with 

 perithecia. 



It is always associated with a small Ulva, probably U. Cali- 

 fornica Wille, and almost as frequently with Enteromorplia 

 minima. Sometimes a patch is almost entirely composed of the 

 composite plants, and again, with almost all either Ulva or Entero- 

 morpha and l)ut a few composite plants. Probably it is either 

 this Ulva or this Enteromorplia which forms the algal portion 

 of the composite plant. The general shape and size of the fronds 

 and hold-fast of the composite suggests Enleromorpha Linza, but 

 in the cross section there is a very decided difference. The cells 

 of the Enteromorpha are much smaller, closer, and more quad- 

 rangular, while the long axis is parallel to the surface instead of 

 at right angles, as in the composite plant. There is no E. Linza 

 associated with the composite or on that shore; so probably that 

 is not the algal part of the composite, as the presence of the 

 fungus could hardly explain such a wide difference in the cells. 



The composite also has a general superficial resemblance to 

 Enteromorpha minima, but a cross section shows a wide differ- 

 ence in structure, especially in size and shape of the cells. This 



