572 THE MICROSCOPE. 



Limneus, the frog, fish, &c. ; another species is met with 

 in the ears of wheat affected with a blight termed the 

 " cockle ;" another, the A. glutinis, is found in sour paste; 

 and another, A. aceti, in stale, bad vinegar. If grains 

 of the affected wheat are soaked in water for an hour 

 or two before they are cut open, the eels will be seen in 

 a state of activity when placed under the microscope. 

 The paste-eel makes its appearance spontaneously in the 

 midst of paste that is turning sour ; but the best means of 

 securing a supply for any occasion, consists in allowing 

 any portion of a mass of paste in which they show them- 

 selves, to dry up, and then lay it by for stock; if at any 

 time a portion of this is introduced into a little fresh 

 made paste, and the whole kept warm and moist for a few 

 days, it will be found to swarm with these curious little 

 worms. A small portion of paste spread over one face of 

 a Coddington lens is a ready way of showing them. 



Planarice: a genus of the order Turbellaria. Some of the 

 species are very common in pools, and resemble minute 

 leeches ; their motion is continuous and gliding, and they 

 are always found crawling over the surfaces of aquatic 

 plants and animals, both in fresh and salt water. The 

 body has the flattened sole-like shape of the Trematode 

 Entozoa; the mouth is surrounded by a circular sucker, 

 this is applied to the surface of the plant from which the 

 animal draws its nourishment. The mouth is also fur- 

 nished with a long funnel-shaped proboscis, and this, even 

 when detached from the body, continues to swallow any- 

 thing presented to it. 



" In imitation of the name bestowed on the trunk of 

 the elephant, the extensile organ serving to imbibe the 

 nutriment of many of the smaller animals is called a pro- 

 boscis, whether it simply unfolds from the root, protrudes 

 from a sheath, or unwinds from a regular series of volu- 

 tions. But in none is the designation equally strict and 

 appropriate as in the Planarice. There it is absolutely the 

 organ of the elephant in miniature, with this exception, 

 that it is neither annulated nor composed of segments. 

 It is of surprising length, being little, if any, shorter when 

 fully extended than the whole animal. It seems of greater 

 consistency, harder, and tougher than the rest of the body 



