Ramaley : observations on egrkgia menziesii. 5 



Anatomy. 



It will not be necessary to discuss at length the structure of 

 other plants in the family Laminariaceas. A rather full bib- 

 liography may be found in the recent articles by Professor Mac- 

 Millan on JVereocystis™ and Lessonia. n 



It may be remarked that no special structural features were 

 noted in Egregia which do not occur in other Laminariaceas. 

 Following Wille 12 the term trumpet hyphas is used as synony- 

 mous with sieve tube, for Wille pointed out that the sieve tubes 

 are merely old trumpet hyphse. In Egregia there is no special 

 sieve tube area at the periphery of the pith web such as has been 

 described in other genera. There were no mucilage canals 

 and no cryptostomata were seen. 



At the present time only a somewhat general account will be 

 given of the anatomy of Egregia. A more complete discus- 

 sion of details of the anatomy and particularly the cytology 

 will be given in a future paper. 



Methods. — Material was hardened in chromic acid solution. 

 The paraffin method of embedding was used and sections from 

 5 microns to 10 microns in thickness were cut. Staining on 

 the slide was found most satisfactory, although some material 

 was also stained in bulk. The sections were mounted from 

 xylene into Canada balsam. By far the most useful double 

 staining for general anatomical work was done with hema- 

 toxylin and Bismarck brown. Flemming's triple stain is also 

 good. 



Holdfast. — Each branch of the holdfast shows, on examina- 

 tion, an external cambium of thin-walled parenchymatous ele- 

 ments. An ill-defined cortex consists of three or four layers 

 of cells similar to those of the epidermis. All these cells may 

 contain an abundance of granular carbohydrate material. The 

 pith comprising the chief part of the structure consists of more 

 elongated cells, but with walls likewise thin. There is no mu- 

 cilaginous thickening, nor are there well-developed trumpet 

 hyphse as in the pith of other parts of the plant. 



Main stipe. — This is a short cylindrical structure, the 

 branches of which form the rachides bearing the prolifera- 

 tions. The outermost ten or twelve layers of cells are thin- 

 walled and merismatic. Next comes the cortical region in 

 which the cells are prosenchymatous and have somewhat thick- 



