XXXIII. OBSERVATIONS ON Gigartina exasperata 



HARV. 



H. B. HUMPHREY. 



The plants used in the preparation of this paper were col- 

 lected by Miss Josephine E. Tilden, in Puget Sound near Seattle, 

 Washington, in August, 1897. 



They are found growing at a depth of six fathoms though thriv- 

 ing in shallower water. In July, 1898, several plants were col- 

 lected near Tracyton, Washington, at a depth of about four 

 fathoms attached to rocks in quiet waters. These plants were 

 generally large and well developed and were somewhat loosely 

 attached to \\$ substratum. Their position in the water was 

 erect except in certain places where a tidal current was present. 

 Plants found in localities washed by swift tidal currents were 

 smaller, thicker and more firmly attached to the substratum. 



The material was preserved in alcohol, consequently the plant 

 could not be studied in its natural condition. All sections were 

 cut by means of a freezing microtome. Material imbedded in 

 gelatin when sectioned proved useless as the cells were swollen 

 to such a degree as to appear unnatural. Portions of the frond 

 were then sectioned directly from the alcoholic solution with 

 good results. 



The stains employed were Delafield's hasmatoxylin, methyl 

 blue, methyl violet, iodine and fuchsin. Delafield's hsematoxy- 

 lin proved a good nuclear stain. Methyl blue was used in stain- 

 ing cell walls but was not as satisfactory as methyl violet. 

 Iodine was used in staining carpospores and brings out very 

 clearly the distinction between them and surrounding tissue. 

 Fuchsin proved a very satisfactory stain used in connection with 

 the study of protoplasmic pits, coloring them a deep red. 



Sections were all treated with staining solution and then 

 mounted directly in glycerine jelly, making a permanent mount. 



601 



