1 1 G J. E. LITTLEBOY — THE BULBOKXE AND GADE, 



every gallon of the river water contains about twelve grains of car- 

 bonate of lime, and six grains of other calcareous matter. The 

 whole of the carbonate of lime, together with a small portion of 

 sulphate, is precipitated by boiling, and this fact will explain the 

 origin of the incrustation that accumulates in culinary utensils in 

 which such water is boiled. It follows, therefore, if my calculation 

 of the volume of water passing Hunton Bridge is correct, that an 

 aggregate quantity of more than 18,000 tons of chalk is annually 

 abstracted from the surrounding Chalk formation and carried 

 away by the water of the Gade, to be again precipitated, or, 

 by the organic agency of minute Foraminifera, to form, in some 

 far-off submarine region, a new Cretaceous deposit, possibly the 

 incipient chalk hills of ages yet to come. I find, by reference to 

 Professor Attfield's analysis, that a gallon of water taken from the 

 chalk well to which I have alluded contains six grains of calcareous 

 matter over and above the quantity found to exist in water taken 

 from the Gade ; bvit this is easily accounted for by the large 

 quantity of surface drainage which that river receives during its 

 course downwards, the water springing from the Chalk formation 

 becoming, in this manner, more or less diluted. 



I extract the following sentence, which seems so aptly to bear 

 on this subject, from Mr. Evans' work on 'Ancient Stone Imple- 

 ments' (page 591): — " Taking the calculation of 17 grains of bi- 

 carbonate of lime to the gallon, it will be found, by calculation, 

 that every inch of rain which falls over a square mile of chalk 

 country, and passes olf by springs, carries with it, in solution and 

 without in the slightest degree interfering with its brightness, no 

 less than from 15 to 16 tons of solid chalk." 



I now proceed to the consideration of the second portion of my 

 subject, viz. the different varieties of fish which frequent the two 

 rivers I have attempted to describe. 



Baron Cuvier has divided all fishes into two great series : 1st, 

 the Osseous Scries, or those which possess a bony skeleton ; 2nd, 

 the Cartilaginous Series, or those which possess a cartilaginous 

 skeleton. He further subdivides these series into six orders, based 

 principally on the nature and texture of the fins, four belonging to 

 the osseous and two to the cartilaginous series. 



Into the particulars of these divisions I do not propose to enter. 

 All the fish which are likely to claim our attention this evening, 

 with the single exception of the lamprey, belong to the first or 

 osseous series. 



I have already stated that the rivers Bult)orne and Gade become 

 incorporated, at difi^erent times, with the Grand Junction Canal. 

 It is therefore necessary, when considering the fishes of the two 

 streams, to include all those which have been taken or observed in 

 that portion of the canal through which they pass. I shall com- 

 mence with the smaller varieties. 



The Three-spined Siickleba.ck [Gasteroste us trachurus). — First 

 upon my list is the rough-tailed, or three-spined, stickleback, and 

 in several respects this tiny creature ranks amongst the most 



