1897] BRIEFER ARTICLES 199 
diatoms and other unicellular alge in a thriving condition. I ascer- 
tained the temperature of the medium in which these organisms were 
| growing and found it to range from 20° to 55° Centigrade. This is 
not remarkably high, but several circumstances in the environment 
seemed to me to be worthy of note. 
| The whole surface of the wall on which the alge were flourishing 
| was covered with freshly formed acid sulfate of aluminum. The 
. steam which issues in large quantity from all the larger crevices in the 
| rocks at a temperature of 100° Centigrade is highly charged with sul- 
E . fur dioxide and is said to contain considerable traces of arsenic in 
| some form. So much vapor of sulfur is also contained in the exhala- 
tions that quantities of sublimed sulfur are to be found crystallized in 
delicate needles about all the crevices or fumaroles. In all cases the 
mixed alg are found growing up to the very orifices of these fissures, 
so that the plants are constantly bathed in the atmosphere just 
described and are constantly subjected to blasts of air and vapor at © 
almost 100° Centigrade. 
I have made no attempt to identify the several species of diatoms 
present. Professor W. G. Farlow has determined the organism which 
constitutes the great bulk of the deposit to be Coccochloris Orsintana 
Meneghini.—J. Y. BercEn, Pozzuolt, Italy. 
