LUMBRICUS. 135 



Soon after the first deposit, a very minute, microscopic animalcule, 

 was visible in the watch-glass. A consider number appeared then and 

 subsequently. The form of these creatures was rather the parallelogram 

 flattened, begirt with cilia. Their length three times their breadth ; their 

 colours faint dingy yellow ; the body generally opaque, but with lighter 

 portions on some specimens. Their motion was rather slow towards 

 the end of June, and sometimes a tendency to revolve horizontally 

 on the centre of the body as an axis. A deep constriction of the middle 

 was seen in several, as if they were about to sunder. 



Under a high magnifier, the cilia' distinctly formed a fringe or bor- 

 der on the margin. A longitudinal channel occupied much of the body, 

 which I was inclined to think commenced by a wide circular orifice, the 

 mouth in the very extremity. 



It proved impossible to follow the history of these minute creatures, 

 perhaps not equalling the thirtieth part of a line. Nor can I pretend to 

 affirm that they were not of the Animalcula infusoria group, fig. 4. 



One specimen survived eighteen months, when it perished acci- 

 dentally. 



PLATE XVIII. 



FIG. 1. Lumbricus cirratus. 



2. Section of a cirrus. 



3. Ova. 



4. Animalcula. 



b. LUMBRICUS MARINTTS ARENICOLA PISCATORUM Lug Worm 



Plate XIX. 



The inhabitants of the sea- coast, or those who frequent the wet and 

 shallow shores of Scotland, cannot avoid remarking certain places almost 

 occupied by pyramids or rolls of mud and sand cast up, as the tide conceal- 

 ing them recedes. In some quarters these are extremely numerous, of 

 unequal size and quantity, in others they are proportionally rare ; but in 

 all it is evident that considerable humidity favours their production. 



All these heaps proceed from an animal lurking at a considerable 



