Marsh. 195 



oyster requires about fifty thousand times its weight of 

 water to obtain the mineral matter necessary for the forma- 

 tion of its shell. With such numbers as these one can soon 

 account for the disappearance of vast quantities of these 

 shell-making substances. So Father Thames is not so lazy 

 after all. 



The most brilliant denizen of the marshes passes us like 

 a flash. None can compare in beauty with the kingfisher, 

 which, like a sapphire meteor, passes and re-passes us again 

 and again, as it darts up and down the pools and ditches, 

 resting occasionally on a stump stretching 'over the water, 

 but diving off rapidly as it spies its prey, which it eagerly 

 seizes and at once bolts almost whole, unless in some 

 sheltered hole, forsaken years ago maybe by a water-vole, 

 it has a nest and young ones, when the food is quickly 

 carried home. I dare say it has a nest in the bank there, 

 but it would require a very long search to find where it is 

 hidden, and when found it would probably prove a still 

 more difficult task to get it out. There is a smart little 

 bird in a bright coat of yellow, tinged with red, its back 

 spotted, the crown of its head pale, but the sides black. It 

 is not a reed- nor a sedge- warbler. It is rather a con- 

 spicuous fellow, but this is the first I have noticed ; I 

 dare say it is the aquatic warbler, a much rarer bird than 

 its fellows. This reminds me that a few winters ago I saw 

 the beautiful but rare waxwing, with its bright, red-tipped 

 feathers, on the edge of this selfsame marsh ! 



Yonder is a heron, its grey livery rendering it almost 

 invisible against the mud-banks despite its great size, 

 and very different from the starlings standing on the 

 sheep's backs yonder which are picking the ticks from the 



