77 
The first question has already been answered in the affirmative 
by Reinke, Bonnier, Bornet and others. The second will receive. 
some further consideration. As far as lichens are concerned in- 
vestigators are quite generally agreed that the fungal symbiont 
can no longer lead an independent existence. It is absolutely 
dependent upon its symbiotic association with the algae. It is also 
generally believed that the algae (gonidia) can exist independently. 
At least, many of the lichen-algae have been cultivated in artificial 
media. Some recent experiments in this line would lead me to 
conclude that the algae of some of the higher lichens can not exist 
independently for any considerable period of time. . It became ap- 
parent at once that related single-celled algae occurring free in na- 
ture develop more readily than the lichen-algae when placed in or 
on artificicial media. Repeated attempts to cultivate the algae 
(Cystococcus humicola Nig.) of Cladonia have only partially suc- 
ceeded. The algae would soon acquire an impoverished appear- 
ance; changing from bright green to yellowish green and finally 
toa pale straw color. Cell-division occurred only rarely and at 
long intervals during the beginning of the experiment. Soon cell- 
division and growth ceased altogether. In some of the experi- 
ments a species of natural algae (Profococcus viridis and another 
Species) accidentally introduced developed rapidly, soon forming 
a green layer over the substratum (schistose rock, sandstone, lime- 
stone). These natural algae frequently occur upon the surface of 
the lichen-thallus and are apt to gain access to the culture media. 
They can, however, readily be gotten rid of by the isolation 
method. Culture attempts with algae (Cystococcus humicola Nig.) 
from several species of Parmelia gave similar results. In no case 
was it possible to develop a colony of, any considerable size nor 
could the growth of the culture be maintaned for any considerable 
period of time. From these experiments the conclusion seems 
justifiable that the algae of some of the higher lichens are no longer 
capable of leading a continued independent existence. Fungus 
and alga, during their association as lichen, have become mutually 
adapted so that they are complimentary in their relationship as a 
morphological whole. It is safe to conclude that at least some of 
the lichens form absolute individualism. Even the most prejudiced, 
therefore, cannot hesitate in recognizing such lichens as morpho- | 
