112 DR. J. W. HESLOP HARRISON ON 



series of meandering grassy channels in the recesses of the 

 marsh called "stells." They now contain water more or less 

 fresh, but which becomes very perceptibly brackish as we 

 approach Greatham Beck. Although the water level alters 

 slightly according to the season, the change to a casual glance 

 is not apparent. If, however, one follows the fleets backward, 

 it will be discovered that they branch and lead into the little 

 grassy stells which in turn pass imperceptibly into the general 

 level of the " marsh " — using the term not because it is a 

 marsh now but because it was so formerly. It is in these 

 stells, not the greater ones connecting up the several fleets, 

 that any alteration in water level betrays itself, for in summer 

 the water vanishes, and they becomes grassy depressions 

 differing but little outwardly from their surroundings, except 

 in the darker green of their vegetation. 



Hohne Fleet. 



By virtue of its superior size and greater depth, and 

 favoured by the comparative freedom of its waters from salt, 

 the Flora of Holme Fleet is much richer than than that of the 

 other three. 



Moreover, the amount of silting up it has undergone is 

 quite negligible, comparisons made between the six inch 

 Ordnance Map of i860 and the conditions of the present day 

 showing quite unimportant changes. This stability results from 

 its superior depth in the first place, maintained subsequently 

 by powerful hydrodynamic agencies set in motion by the wind 

 which retain the silt in a perpetually suspended condition ; 

 this, naturally, means that the water is nearly always turbid. 

 The great wind forces brought into play are further emphasised 

 by the almost total absence of vegetation on the north side 

 and its concentration to the south and east. 



I have no exact measurements of its depth ; still I am 

 assured by my friend Milburn, who has traversed it in a boat 

 and made rough soundings with a pole (and had unfortunate 

 wading experiences in it !), that its maximum depth exceeds 

 20 feet. Further, he tells me that, beyond the limits of the 



