FUNGI. 



295 



Fig. 58. — Ophidomonas sanguiiiea. 



in summer, since it is so common, but when this colour 



changes, often in a single night, and passes from 



sreen to red, the unaccustomed tint excites wonder, 



although it is caused by 



the same plant which was 



green the day before. If 



there is a thunderstorm or 



waterspout, which draws 



up the red water from the 



ponds and reservoirs, and 



discharges it in the form 



of rain on the surrounding 



country, we hear of the 



phenomenon that it rains 



blood, and it would be easy to find in the drops of 



rain the reddish microbe which imparts this colour 



to them."^ 



We have in remembrance an incident which 

 occurred in a remote country village some years ago. 

 It was a warm summer day when the report reached 

 us that the villagers were deeply concerned as to a 

 neighbouring horse-pond, which was really almost 

 stagnant, and much reduced by the summer heat. 

 The circumstance which caused alarm was that a 

 large portion of the surface every day assumed a deep 

 blood-red hue, and speculation was rife as to the 

 cause. Out of curiosity we went to see the phe- 

 nomenon, and saw the irregular, somewhat shifting 

 red patches. At once suspecting the cause, we 

 secured some of the water in a wide-mouthed col- 

 lecting bottle, and the microscope soon revealed 



* E. L. Trouessart, "Microbes, Ferments, etc.," p. 128. 



