152 Prof. Ehrcnherg on Fossil Infusoria. [Jan. 



several feet deep, and much developed in small holes and in the foot- 

 steps of animals grazino-. This mass is extremely delicate, and with- 

 out any consistency, dividing itself at the least touch into an indefinite 

 number of parts. Where it has become dry, after the evaporation of 

 the water, it appears exactly like oxide of iron, for which it has been 

 formerly often mistaken. We perceive however under the microscope, 

 with a moderately high magnifying power, extremely slender articu- 

 lated threads, the members of which measure only titoo" of ^ Vw^Q, and 

 in which the yellow colour is inherent. At the beginning of last sum- 

 mer I satisfied myself that these slender articulated threads do not 

 lose their form in a strong red heat, but the colour changes to a red- 

 brown, which is exactly that of iron-oclire. It was found that by 

 the application of muriatic acid the colour was dissolved, without the 

 articulated threads being changed : in the solution i)recipitated iron 

 was clearly visible. There is also one of the genus Gaillonella, very 

 similar to the Bacillaria, but a very minute organic being, containing 

 a yellow ochre colour, in which there is probably a great proporlion of 

 iron, in the same manner as phosphate of lime is contained in the bones. 

 By extraction of the lime, the gelatine of the bones retains, as is well 

 known, its form : in the same manner the Gaillonella ferruginea 

 possesses a siliceous shield, which retains its form unchanged after the 

 extraction of the iron. 



I have, already examined with the microscope various specimens of 

 the Raseneisen from Berlin, from the Ural, from New York, and other 

 places, and find the extremely voluminous yellow iron oxide which is 

 attached to them, and which perhaps has originally served to form 

 them, to consist also of similar connected threads in rows, which re- 

 semble the Gaillonella in size, form, and colour, and which are not 

 destroyed by the action of heat or muriatic acid, but no longer form 

 such evident articulated threads as in the living animal. If 1 compare 

 it, when its fibres are disjointed, with the Gaillojiella distans in the Po- 

 lirschiefer, I find no reason to consider the pheenomenon in the Wiesen- 

 erz-ochre as a different one. I received, through the kindness of 

 M. Karsten, the vegetable products of the mineral water of the salt- 

 works of Colberg, in which there is a yellow earthy substance, in great 

 quantity, formed on the surface. At first it collects at the surface of 

 the stagnant v*-ater, as I was informed, in a greenish mass, similar 

 therefore to the protoxide of iron. Dried and exposed to the air it re- 

 mains of a beautiful ochre yellow, and on being heated it becomes of a 

 red-brown blood-stone colour On dissolving it in muriatic acid I 



