F. R. Pethehbridge 509 



P(ili/(/(iin(iii (iiiiphihiiiin usually floats and reaches the surface of the 

 water in which it grows, so from the length of these plants (many of 

 which were over nine feet long) it was possible to tell the depth of the 

 water on the difl'crent fields. Most of the plants were carrying a good 

 supply of seed so that it may prove troublesome during the next few 

 years. It caused more hindrance to ploughing than the "blanket 

 weed." 



Chira hispida was present in great abundance for a distance of about 

 sixty feet on each side of the dykes. Sometimes it was abundant on 

 one side of the dyke and not on the other. On the rest of the field only 

 small patches could be found (PI. V, fig. 2). 



Another smaller species of iliani was found but not very 

 frec]uently. 



As the remains of the Chiiras are almost entirely composed of 

 calcium carbonate, they should prove of considerable value in neutral- 

 izing the acidity of the soil, and it will be interesting to note in those 

 fields which receive no dressings of lime, chalk, or similar materials, if 

 the crops grow better where the deposits of Chiirn were thickest, viz. 

 near the dykes. 



In places, Alisma plantago, the water plantain, was prevalent and 

 had set seed (PI. VI. fig. 3). 



Occasional plants of Typha lulifolut were met with, but these were 

 cut down before the land was ploughed. 



On the dyke sides Arundo phraginifes was growing .luxuriantly. 



The following is a list of the plants found on the arable land: 



Pobiyonuin ainphibitim Polygonum avkulare 



Alisma plantago Veronica beccabunga 



Tijpha la/ifolia Ranunculus agvatilis var. 



Mentha arpiatica Oenanthe fluviatilis 



Agropynim repens Lythrum saUcaria 



Aqrostis alba Senebiera coronopus 



Cnicus arvensis Rumex hydrolapathum 



Oallilriche verna var. Glyceria aquatica (near the dykes) 



Grass Land. Two pastures were examined, situated respectively 

 near the farm buildings of Peckett's Farm and Turf Fen Farm. On 

 both of these all the useful grasses were killed. Both were thickly 

 covered with "blanket weed," and occasional specimens of Poh/gonum 

 amphibium were found. Agropynim repens was present in abundance, 

 and occasional specimens of Agrostis alba were found. 



At Turf Fen Farm, Potentilla anserina was fairly abundant, as was 



