499 
the naked eye. No cyphellae occur near the actively growing tip 
of the thallus. 
Acharius applied the term cyphellae to the form first described. 
Those of the second form he considered to be soredia. Ny- 
lander retained the name cyphellae for the first form. The second 
form he designated as psuedocyphellae. There is no morphological 
or physiological reason why the latter should be designated as 
“false.” Indeed it were more consistent to designate the first 
form as false since they are of less frequent occurrence. Stitzen- 
berger* retains Nylander’s distinction into true and false cyphellae 
and further subdivides them as to color into white and yellow. 
This subdivision seems to be valueless, since their color depends 
upon the color of the medullary hyphae. Stitzenberger considers 
_ them of special importance in his classification of the Stictei. I 
am, however, opposed to adopting as primary, morphological 
characters whose physiology is unexplained. 
Having thus briefly treated of the morphology of cyphellae we 
will now refer to their probable physiological significance. As 
already stated, they very likely serve to admit air into the interior 
of the thallus. Some of the older lichenologists looked upon them 
as vegetative propagative organs, similar to the soredia. They 
are not soredia, since they usually contain no algae. That the 
second form may accidentally contain algae is possible, since we 
find occasional algae throughout the medullary layer. It is, how- 
€ver, unreasonable to suppose that they would normally contain 
algae, since their position is not suitable for the development of the 
Symbiotic algae. From the nature of the cortical layers and the 
epidermis in the majority of Stictei, it is reasonable to assume 
that the cyphellae serve a function similar to that of the stomata 
of ordinary foliage leaves. That is, the cyphellae and breathing 
Pores of lichens are functionally similar. If it is scientific to make 
any comparison of the morphology of lichens and phanerogams it 
may be stated that the cyphellae are analogous to lenticels.* The 
tissue which closes the opening in the lower cortical layer is the 
result of a special cambial or meristematic activity. 
beste 
*Stitzenberger, E. Die Gruebchenflechten (Stictei) und ihre geographische Ver- 
breitung. Flora, 81: 88-1 50. 1895. : 
> © This anal ne was pointed out by Dr. Smith Ely Jelliffe at a recent meeting of the 
: -Togrey Botanical Club (November 5th). 
