Nov., 1909.] Potato Agar. 13 



THE LABRADOR TEA IN OHIO. 



Otto E. Jennings. 



In the Ohio Naturalist for December, 1908, Professor J. H. 

 Schaffner presents a list of "Plants on the Ohio State List not 

 Represented in the State Herbarium" and proposes to strike 

 off these names if no proper evidence of the occurrence of the 

 plants in question in Ohio is forthcoming. 



Yesterday there came to my hands from my friend, Mr. Ros- 

 coe J. Webb, of Garrettsville, Portage County, Ohio, specimens 

 of three plants which he and Mr. A. D. Robinson, of Ravenna 

 had collected in a tamarac bog near Shalersville, Portage County, 

 May 24 of this year. The plants were Wolfitia columbiana Karst., 

 Ilicioides mucronata (L.) Britt., and Ledum groenlandicumOeder. 



Mr. Webb says the Ledum is abundant at this place and that 

 he has known of this locality for about ten years. The specimens 

 sent me were in good flower and were evidently taken from 

 plants in vigorous condition. This record is noteworthy in that 

 Mr. Webb's station evidently constitutes the only authentic 

 occurrence of the plant in Ohio. However, the writer has dis- 

 covered a patch of Ledum, about one-half acre altogether, in 

 the great Pymatuning Swamp, near Linesville, Pennsvlvania, 

 and only about six miles from the Pennsylvania-Ohio state line, 

 and it would not be surprising if other stations should be found 

 for this species in other bogs in northeastern Ohio and north- 

 western Pennsylvania. 



Carnegie Museum, Pittsburgh, Pa., May 27, 1909. 



POTATO AGAR. 



Mel. T. Cook. 



The making of potato agar probably presents greater annoy- 

 ances than the making of any other medium used in bacterio- 

 logical and mycological laboratories. The difficulty is due to 

 the starch of the potato becoming gelatinous and difficult to 

 filter. For sometime the writer has been using a method which 

 has proved very satisfactory. This method is a modification of 

 the method in general use and it is probable that other workers 

 may be making agar in practically the same manner. However, 

 it has been considered advisable to publish it at this time for the 

 benefit of any who may be experiencing difficulties in the making 

 of this very valuable medium. The method is as follows: 



A. — Melt the desired amount of agar (10, 12, or 15 grams) in 

 500 cc. of distilled water. 



