— 20 — 
result of the parasitism. On the whole the algae thrive better outside the associa- 
tion with the lichen [fungus], while the lichen [fungus] does poorly or dies outright 
outside the association.” 
In an interesting recent paper by W. B. McDougall 1 there is a general dis- 
cussion of^symbiotic phenomena and there is put forward a tabular classification 
of these various relationships. In this classification lichens, together with endo- 
trophic mycorhizas, root tubercles, and leaf tubercles of Rubiaceae, are included 
as examples of reciprocal nutritive conjunctive symbiosis, i. e., reciprocal para- 
sitism. McDougall says: “The word lichen, however, has been used for a long 
time to mean the composite structure that results from the symbiosis of lichen- 
fungi with algae, and no very good reason has yet been given for changing its 
meaning. A lichen-fungus is a fungus, it is not a lichen. There is no more rea- 
son for calling a lichen a fungus than there is for calling a mycorhiza a fungus; 
and it is just as absurd to call a lichen-fungus a lichen as it would be to call a 
mushroom a mycorhiza.” O. E. J. 
EXCHANGE DEPARTMENT 
Offerings — To Society Members only. Return postage, rather ’than a 
stamped envelope, should be sent. 
Mr. Severin Rapp, Sanford, Florida . — Bilimbia castanella Merrill, sp. nov., 
collected by Mr. Rapp in Florida. 
NOTE 
Owing to scarcity of copy, the January and March, 1919, numbers of The 
Bryologist have been smaller than usual, but it is expected that the normal 
number of pages will have been published by the end of the year. We would 
ask that you let us have your notes and articles, even if they are brief. Write 
up notes about what you have seen and found — others among us are sure to be 
interested in these things, too. Also, will you not get together material to 
offer in the Exchange Department and build up collections of your own? If 
you have not started your own collection of mosses or hepatics or lichens, you 
will probably not have realized what pleasure it might give you and what an 
added zest it might give you in your walks and visits to the fields and woods. 
Those of our readers who are interested in accumulating specimens from other 
countries will be interested in the sets of hepatics now being issued by Pearson 
from England, and advertised in this number of The Bryologist. 
1 McDougall, W. B. The Classification of Symbiotic Phenomena. Plant World 21 : 250- 
256. Oct. 1918. 
