LITTORAL ALGAE OF PUGET SOUND • 9 1 



Plate 3. — Parts of apetalous summer flowers, and (fig. 4) hairs of 

 lateral petals of spring flowers of Viola candidu'a. 



Fig. I a. — Pistil of apetalous flower with stamens appressed to the 

 stigma. (Side view.) A minute sterile stamen on the left between the two 

 fertile ones. 



Fig. lb. — A fertile stamen with four anther sacs. Pollen escaping 

 from the subapical cleft in the two larger sacs. Rudiment of another sterile 

 stamen at the base. [Magnified about 30 diameters]. 



Fig. 2a. — Cross section showing arrangement of the parts of the apeta- 

 lous summer flowers. A, position of the recurved petiole. B, sepals, sub- 

 equal. C, 2 stamens bearing fertile anthers and inserted always next to the 

 petiole A. (The third sterile stamen is ordinarily absent.) D, ovary with 

 ovules. 



Fig. 2b. — Front view of pistil with two stamens. (Same as Fig. la of 

 another flower without the third sterile stamen.) 



Fig. 3. — Side view of recurved style and stigma showing pollen grains 

 sending pollen tubes into the hollow style. 



Fig. 4. — Hairs of the beard of the lateral petals greatly magnified. 

 The hairs are spirally striate under high magnification and round, not 

 flattened except in age. 



• Dept. of Botafiy, 



University of Notre Dame. 



Some Uttora! Algae of Puget Sound. 



CHAS. O. CHAMBERS. 



The following study was made at the Puget Sound Marine 

 Station, during the summer of 1909, mainly in the months of 

 July and August. A general survey of the ground had been made 

 the previous summer. Its purpose was to determine what types 

 of algae inhabit the tide-pools; why they prefer these places 

 and how they are specially adapted to such places. The study 

 was made with special reference to Prionitis, which seems to be 

 the one prevailing type in all these tide-pools, and showing con- 

 siderable variation with variety of environment. 



The work was suggested and outlined by Professor T. C. Frye, 

 acting director of the Station. No such study had yet been made 

 in this region, though a study somewhat similar in its general 

 character was made by Skinner (8) at Port Renfrew, B. C. The 

 conditions there are quite different, and his study does not attempt 

 to relate types to environment, nor is it specially directed to any 



