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mens with which to compare and the series of articles published in the 
BRYOLOGiSTby Mrs. Harris. The beginner will not need foreign literature, 
but the books written by Tuckerman, Schneider and Willey will be found 
helpful if they can be obtained. As you gain in experience, difficulties will 
clear up, and you will find ways of your own and perhaps better ones than 
some of those suggested above, for no two people work just alike. At least 
do not collect without attempting to determine as best you can, Send speci- 
mens to an expert with your determinations stated on every envelope, even 
if you are no farther than the genus or even the family. You must do this 
for the sake of the satisfaction of it and the strength that it will give. 
The Study at Home. 
But given this table and apparatus and some directions regarding use. 
Just what shall be studied? Regarding the thallus there must be careful 
observation of form, size, color, method of attachment and general relation 
to the substratum, nature of the surface as to whether smooth, wrinkled, 
chinky, areolate, verrucose, etc., the margin as to whether entire, wavy, or 
lobed, etc., and finally the cross-section must be made and carefully studied. 
Then turning attention to the fruit, the general form and size must be care- 
fully noted, the form and color of the disk, the nature and duration of the 
exciple or exciples, and the manner of attachment of the fruit to the thallus. 
Then the sections may be resorted to in order to ascertain the nature of the 
exciple, the hypothecium, the paraphyses, the asci, and the spores. And, 
finally, it will be found to be an excellent exercise to attempt to write a 
description of a lichen occasionally bringing out all the points observed. 
After a few descriptions have been written, those in manuals of lichens will 
mean more to the student, for they will not appear so vague as soon as the 
powers of observation and discrimination are thoroughly developed. Some- 
times one can put some special “ ear mark” into a description, but often two 
.species are somewhat different in a number of points, but not very much so 
in any one particular respect. In such instances, the attempt to show the 
special “ear mark” will be a failure, and the decision between the two spe- 
cies may be by no means easy for the most competent student of lichens. The 
beginner must always see the spores in the asci, as he is otherwise very 
likely to get the spores of some other lichen occasionally and make a stupid 
failure in the determination. And the student must be warned not be expect 
to find sections like many of the drawings in some manuals of lichenology. 
Many of these figures are diagrams, which show what might be seen in ideal 
sections. They serve their purpose, but the student will usually have to be 
content with seeing things much less distinctly. Finally, after the begin- 
ner has done his best, he will often have to be satisfied with tracing his plant 
to the genus or family rather than to the species ; but he need not be discour- 
aged at this, for experience will make him more and more able to determine 
species. Every manual of lichens has some peculiarities that need explana- 
tion. And perhaps the uses of the terms pale and cloudy , as applied to the 
hymenium and the hypothecium in the descriptions issued by the present 
writer, need special explanation. In ordinary sections the lightest colored 
areas in these tissues seem whitish, whereas, if the sections were thinner, 
