50 Henderson — Comparative Study of Pyrolaceae and 



Methods and Materials Used 



In making comparisons, care was taken to section the material 

 at exactly the corresponding point in each of the plants. 



Sections of freshly gathered or of alcoholic material of rhi- 

 zomes, stems, and leaves were examined unstained in acetic 

 acid, or stained in safranin and methyl green and examined in 

 balsam. 



Fresh root tips were examined in a solution of iodine in potas- 

 sium iodide to differentiate the fungus. Otherwise, all roots 

 and flowers were fixed in weak chrom-acetic acid and embedded 

 in paraffin. These were stained in safranin and gentian violet. 



Pieces of the ascending axis of Monotropa uniflora and M. 

 hypopitys were bleached and macerated in a mixture of 50% 

 nitric acid and potassium nitrate in order to examine the epi- 

 dermis. 



Herbarium material of the flowers was prepared for exam- 

 ination by the method used by R. C. McLean (52). 



The following is a list of the plants used, and localities from 

 which they were collected, for use in this comparison: 



Fresh Material 



Chimaphiia umbellata — Hosensack, Pa., Analomink, Monroe 

 Co., Pa., Somers Point, N. J., Glendora, N. J., Woods Hole, 

 Mass., Greenwood Lake, N. Y. 



Chimaphiia maculata — Hosensack, Pa., Crum Creek, Dela- 

 ware Co., Pa., Almonessen, N. J., Blackwood, N. J., Somers 

 Point, N. J., Woods Hole, Mass. 



Pyrola rotundifolia — Hosensack, Pa., Crum Creek, Delaware 

 Co., Pa., Analomink, Monroe Co., Pa., Woods Hole, Mass. 



Pyrola elliptica — Hosensack, Pa., Crum Creek, Delaware Co., 

 Pa., Analomink and Paradise Valley, Monroe Co., Pa., Woods 

 Hole, Mass. 



Moneses uniflora — Plants collected by Miss Mary Garley near 

 Claremont, N. H. 



Monotropa hypopitys — Analomink, Pa., Somers Point, N. J., 

 Woods Hole, Mass. 



Monotropa uniflora — Analomink, Pa., Blackwood, N. J., 

 Woods Hole, Mass. 



Kalmia latifolia, Kalmia angustifolia, Dendrium buxifolum, 

 Cassandra calyculata — Clementon, N. J. 



Ledum groenlandicum — Peakes Island, Maine, collected by 

 Miss A. M. Russell. 



