THE AMERICAN 



MONTHLY 



MICROSCOPICAL JOURNAL. 



Vol.. XVI. MARCH, 1895. No. 3. 



An Artificial Key to Licliens. 



By L. A. WILLSON, 



CLEVELAND, OHIO. 



The object of the following key is to enable a micros- 

 copist to determine the genua of any lichen from any of 

 the various spores that pertain to the plant. To see the 

 spores or the tissues, it is not necessary to make sections. 

 Remove an apothecium, soak it in water, then remove 

 the specimen to a slide, cover it with a drop or two of 

 potassium hydrate, macerate, spread it out thin, add a 

 drop of fresh water, cover and examine with a quarter- 

 inch objective. It is a beautiful study. The numbers 

 attached to the genera are those of Tuckerman's Synop- 

 sis of Lichens. 



No naturalist and especially no microscopist should 

 fail to have some knowledge of every department of na- 

 ture. It is humiliating to a naturalist when at a picnic 

 or field meeting, to be asked about lichens and to be 

 unable to respond. 



KEY 



1 Sp. granulose 13 Umbilicaria 



2 Sp. cylmdraceous, long 34 Conotrema 



3 Sp. eight locular 64 Normandina 



4 Sp. cymbiform 68 Sagedia 



5 Sp. dactyloid A 



6 Sp. simple B 



7 Sp. spherical C 



NOTE. — Owing to the frequency of occurence of these words, Apothecia 

 will be abbreviated to Apo., thalus to th., and spore to sp. — editor. 



