236 FIRST FORMS OF VEGETATION. 
tinged with them of a carmine or deep orange 
hue. Ehrenberg frequently observed in the 
steppes of Siberia, lakes and other collections of 
water filled with red algez. ‘In a fen,’ he remarks, 
‘with a pool of water, the dark-red blood colour 
was very striking even at a distance. This colour 
I found on examination was confined to the slimy 
surface, which in different places formed a shining 
skin. The red colour was darkest at the edge of 
the marsh. How many a wonderful fairy tale 
has science divested of its gilded ornaments, and 
converted into hard fact and unvarnished truth! 
And how many a phenomenon, magnified by the 
unthinking ignorance and credulity of vulgar 
superstition into an evidence of supernatural 
agency, and an omen of future calamity, has the 
microscope resolved into a mere collection of 
minute and simple vegetables, or equally harm- 
less animalcules ! 
There is a startling thought suggested by these 
accounts of blood-prodigies. Occurring as most 
of them did before the outbreak of epidemics 
which they were supposed to herald, and on 
account of which they were called signacula, they 
obviously point to the conclusion that they were 
developed by abnormal conditions of the atmos- 
phere. In ordinary circumstances, but few either 
of the animals or plants which caused these 
