604 MINNESOTA BOTANICAL STUDIES. 



tungen" on the ground that upon investigation of the original 

 specimens they are proved to be young stages of various algae, 

 but particularly of the Phycochromaceae. 



In a later work Hansgirg (IV) quotes his own remarks con- 

 cerning Pilinia from his paper in Flora and mentions a new 

 species of Pilinia (P. minor) as described by himself (III). 

 The same species is given as new in a review of an article by 

 the same author (V). As access cannot be had to these two 

 descriptions, further discussion of them will be omitted. 



Description of the Bellefonte Spring. This spring is 

 famous both for its size and the purity of its water. It is 

 sixty- five feet in width, eighty-five feet in length, and eight 

 feet in depth. Year after year, without variation, it dis- 

 charges 14,600 gallons of water per minute. Not only does it 

 supply the town of Bellefonte with water, but its power is used 

 to pump water up a hill to a distributing reservoir, and then 

 the quantity going to waste is large, "making a stream like a 

 mill tail." Its temperature remains nearly unchanged during 

 the different seasons, being in winter 51° P. and in summer 52° F. 



Through the kindness of Mr. Portney, the following extract 

 from the report of an analysis of the water was obtained: 



Total solid residue 152. 3 parts per million. 



Of which was lost in ignition 36.3 " 



Leaving freed residue 116.0 " 



Degree of hardness 11. " 



Poisonous metals Absent. 



Color None. 



Odor None. 



Free ammonia 0.023 parts per million 



Albuminoid ammonia 0.044 " 



Oxygen required for moist combustion. 0.7 " 



Chlorine 7.84 



Nitrogen as nitrates and nitrites Absent. 



The spring is fed by an underground stream pouring in at 

 the south-east corner and passing out at the north-west corner. 

 There is no perceptible current in the water except at the 

 immediate outlet. These conditions have their effect upon 

 the nature of the algal growth in different parts of the 

 basin. Pebbles taken from the running water in the 

 north-west corner of the basin were covered with species 

 of Oscillatoria with not a trace of Pilinia among them. 

 Around the inlet there is no vegetation of any kind. A species 

 of Chara grows on the bottom. The pebbles bearing the 



