— 40 — 



I have outlined in a previous paragraph something of the prerequisite?; 

 to good work in the field, and with these alone one may obtain results that 

 will prove of great interest and value. But there are other phases of the 

 subject which need attention. These are morphological and physiolog- 

 ical, and through such studies only can we hope to solve completely the 

 adaptation of lichens. Albert Schneider's Text-Book will furnish Americans 

 much of value in such investigations, and the writer's Minnesota papers 

 attempt to discuss to some extent the relation of structure and function to 

 environment. I have suggested a knowledge of the literature as a pre- 

 requisite to the study of the distribution of lichens without citing names of 

 authors or works. In the less generally known field of structural and physi- 

 ological studies of lichens it may be well to make mention of some European 

 authors. In giving a short list one must omit much of value. However, I 

 shall venture to refer to the works of G. Bonnier, M. Funfstuck, H. Jumelle, 

 G. Krabbe, G. Lindau, J. Reinke, S. Schwendener, and H, Zukal. These 

 men have not had ecologic distribution chiefly in mind in their studies, but 

 one will find much of value bearing upon the subject in their writings. 



In such studies as I have suggested one may well confine his researches 

 to a limited area with most excellent results. It is possible to do good work 

 in an area of moderate size in a single season only after one has had years 

 of experience in observing and studying lichens both in the field and in the 

 laboratory. Indeed there is room for extended stndy of lichen formations of a 

 given type, as those of the smooth bark, those of the rough bark, those of 

 the bowlders, those of the earth, those of the calcareous rocks, or those of a 

 given genus or even species of tree. In fact it is only when we confine our- 

 selves within reasonably narrow limits that very minute details can receive 

 attention. Thus while working a number of years in the same area and 

 even on the same formation new problems will constantly arise to renew the 

 worker's zeal. I am certain that my papers recording ecologic studies in 

 Minnesota can not be more than suggestive of what may be accomplished. 

 The field is a most fascinating one, and I confidently look for the day when 

 it will be sufficiently occupied. Let me urge those who have or are able ta 

 acquire a knowledge of the lichens of a limited area to turn their attention 

 to ecologic studies. Fayette, Iowa. 



CURRENT BRYOLOGICAL LITERATURE. 



; A. J. Grout. 



In the Bulletin of the Torrey Botanical Club for February, 1902, Mr. R. 

 S. Williams describes two new mosses, or rather describes two mosses as 

 new — Eurhynchiu7n Taylorae and Brachythecium Fringlei. 



The first is the extreme development in point of size of that extremely 

 variable species, E.fallax (R. & C.) Grout. This species is about as varia- 

 ble and perplexing as E. stoloniferMin (Hook) J. & S. which has given rise 

 to so many "new species." Size alone can scarcely be used as a character 

 on which to base a new species when all intermediate gradations are fre- 

 quent. It may be that this form is entitled to varietal rank as an aid to the 



