CHAPTER OF VARIETIES. 325 



standing upon the wash-hand stand in my bed-room the other evening, 

 I observed by the aid of a candle that several of these black lines had 

 collected at the bottom since morning, and I remarked a small red worm 

 (the blood worm of anglers) with its body half protruded and stretching 

 itself to the right and left at the entrance of these earthern tunnels. 

 Having watched their proceedings I observed that they frequently with- 

 drew themselves to within side, and almost immediately after would 

 come out as before and proceed to collect together the dust and other 

 atoms which had been deposited by the water, and these were added to 

 the extension of the tunnels. Their proceedings bear no little resem- 

 blance to those of the clothes-moth ( Tinea pellionella, &c.) and like 

 them they live in separate apartments. Their tunnels never interfere 

 with each other, from the following reason. As each of them appro- 

 priates to itself all the dust, &c., which it can collect in its progress, it 

 consequently leaves a clear track behind and on both sides of it (see cut}, 

 upon approaching towards which its fellows upon finding a clean surface 

 destitute of the materials they seek, alter their course and proceed in 

 another direction j from which circumstance some of these tunnels may 

 be observed to be bent, or running at right angles, whilst others direct 

 their course from the bottom of the vessel up 'to its sides. They pro- 

 ceed very rapidly in their work, and it is surprising that they do not 

 in their movement upset their frail fabric of atoms, but perhaps when 

 they move withinside they contract the width of their bodies, and thus 

 avoid jostling against its sides ; or it is not improbable that the materials 

 are held fast together by some glutinous substance insoluble in water. 

 The latter opinion I would the more readily adopt, as the grubs of the 

 common gnats (Culicidcz) which are closely connected to these, have 

 the hairs of their beautiful fringed tails covered with oil so as to repel 

 the water from that part, there being situated their respiratory organs ; 

 and that they are provided with a supply of this oil is evidently clear, 

 for Swammerdam discovered that when it was rubbed off, the grubs put 

 their tails within their mouths for the purpose of replenishing them with 

 another coating. While upon this subject, I will mention a circum- 

 stance which I once heard from the lips of a gentleman from whom I 

 some years since not only received academic tuition, but also imbibed 

 that taste for natural philosophy which while I live I hope will increase 

 with my years and add fresh pleasures to my existence. About a year 

 ago, I was invited to attend one of his lectures at his residence in the 

 New Kent Road, when in his discourse he mentioned that a leaden 

 cistern of his having become perforated with smal!4ioles, he was induced 



