BhodUed Colour of Water. 847 



ing^ even at a distance- I tlicrcforc during breakfast made an 

 excursion to the place of the phenomenon. I found that the 

 colour was confined to a slimy surface, which in different places 

 formed a shining skin. In some places the water was troubled 

 with red colouring matter, which in many places passed into H 

 greenish hue. The red colour was darkest on the etlge of thff 

 marsh. In some spots, indeed^ it formed a red jelly, because 

 the water began entirely to evaporate, leaving nothing but sHme 

 upm the mud. Tlie main design of our journey, and the rOe* 

 jwdity with which we travelled, prevented me from making vo^'ny 

 croscopic observations on the spot itself, but I collected the red 

 mass partly on white paper, drying it quickly in the sun, and 

 porOy in glass bottles; and to make certain of preserving 

 some of it fresh, I took with me some of the mud of the fea 

 coloured with this matter, hoping, on the one hand, that the 

 mud would for a long time preserve the moisture, and, on the 

 other hand, that the small and very probably organic particles of 

 colouring, would remain in it undisturbed, and not be destroyed 

 by the jolting motion of the waggon. In Schlangenberg, where 

 we stoppetl longer, on the following day, 25th July (6th August 

 O. S.), and on the 27th July (8th August, O. S.), I had suffi- 

 cient leisure to examine the substance repeatedly witli the mi- 

 croscope, and to make a drawing of it. Tlie corpuscula in thd ^ 

 mud only were preserved alive, and the microscope immediately 

 shewed that tin) colouring particles were infusoria, nearly re- 

 lated to the proteal forms of the Cercaria viridis of Mullcr^ 

 which I have placed in a new genus Evglcna, but they were 

 not, T\\.c these, supplied with eyes^ for which reason I have as- 

 signed them a new generic name, Astasia, from the changeable- 

 Ae&s of their form. Bory de St Vincent has indeed formed » j, 

 genus Ilaphanella, in which he has included similar forms, ami f 

 likewise the Cercaria viridis ; but I omit tbis name, first be- 

 stow^ by him from the form of the aninval, which is MuU^f'f ^,, 

 Proteus tenax. The remaining forms, which are quite different- 

 ly organized, belong to other genera, and partly to other classes. 

 I sl^all give a coloured drawing of this bea\^lif^l f^nim^cule, 

 done from life upon the spot, in the notices which I inrtend pub- 

 Irahing of that journey, but I shall herp be satisfial to make 

 ttisycif intelligible by a sliort characteristic of it. 



