146 THE MICROSCOPE. 



lations wind themselves through the water with rapidity. Each appa- 

 rent hair is a collection of animals bound together by a pliant band ; 

 thus, as they are individually so small, little is known of their struc- 

 ture. Still they form very interesting objects to view ; their very 

 minuteness claiming attention, while their activity and motions excite 

 surprise. The species are numerous, as represented at No. 1, fig. 95. 

 One in particular has been the especial subject of investigation by the 

 medical microscopist : it is somewhat of an oval shape, and found in 

 many forms of diseased structure ; doubtless it precedes or leads to the 

 entire destruction of the tissue it is found in. This shape of the 

 curious little animalcule, it should be observed, is confined to animal 

 substances ; whereas the long, or hair-shaped, is generally to be met 

 with in the disorganisation of vegetable matters. 



These hair-like animalcules were very accurately described by Baker, 

 who ascribes the discovery of them to Mr. Anderson. He says : " They 

 were discovered in a large ditch running into a river near Norwich, 

 the bottom of which was covered with them to some thickness ; when 

 first examined, being motionless, they were taken for vegetable fibres ; 

 but on keeping them under the microscope, and occasionally viewing 

 them, they were seen to move in various forms." 



ASTASIJEA. 



Astasia. Astasia, signifying without a station, in contradistinc- 

 tion to those living in groups, is the term given to a kind of crimson- 

 coloured animalcule the 350th of an inch in length, that exist in enor- 

 mous numbers, and give the waters in which they live the appearance 

 of their bodies. 



Astasia Hcematodes. The blood-like astasia is first of a green 

 colour ; but as it matures, becomes red, the tint by which it is desig- 

 nated. 



Astasia Viridis. On the surface of ponds and stagnant waters 

 is sometimes seen a crimson covering, which, when examined by a 

 microscope, is found to consist of a mass of oblong blood-red eye-ani- 

 malcules the 300th of an inch in length. Ehrenberg states, that in the 

 early part of their existence they are green ; and that the red and green 

 spots on their bodies are caused by the condition of the eggs at different 

 periods in their stomach-cells. A sparkling red eye is possessed by the 

 living atom ; and a cilium proceeding from its mouth gives it motion, 

 sometimes in a straight line, at others rolling about in all manner of 

 ways. When two cilia are seen, then the animal is about to divide 



