40 



plant in neighbouring parishes, and wondered at never having 

 seen it in my own, till it struck me that it was only on limestone 

 soils that I had elsewhere noticed it ; and on going to the only 

 probable locality I found it in profusion. The patch of Cal- 

 careous Sand did not, somewhat to my disappointment, contribute 

 a single plant, though I examined it somewhat carefully, and I 

 did get two species of mosses which I had not met with 

 elsewhere. 



I have myself seen the introduction of one plant into the 

 parish Carduus eriophorus. Just on the opposite side of the 

 little nameless stream which forms our boundary for some "dis- 

 tance is a field, in the parish of Bishop's Caundle, where it 

 grew in abundance ; but though thousands of seeds must have 

 been carried off in various directions by the winds, I never saw 

 a plant of the thistle in Holwell till two years ago. As it has 

 tl selected " a piece of waste ground for its new habitat, I hope 

 it has a chance of life in the struggle for existence ; and all the 

 more, because there is a probability of its disappearing from the 

 former locality through " improvements." These have already 

 destroyed the only locality in my neighbourhood where I ever 

 found Samolus Yalerandi. 



The river, which has at last been crossed by the thistle, has 

 proved, so far, an insuperable barrier to other plants. I can 

 stand at a particular locality and see half-a-dozen plants or so on 

 the other side, on soil in every respect identical, not one of 

 which occurs where I should like to find it ; such as Linaria 

 spuria, Centaurea Scabiosa, and even Laniium album. 



If soil has anything to do with the colours of plants, as I 

 suppose it undoubtedly has, it may be of interest to mention 

 that I have found white varieties of the following plants on 

 Oxford Clay : Primula vulgaris, Centaurea nigra, Carduus 

 arvensis, Scilla nutans, Bartsia odontites, Scabiosa succisa, and 

 Erythrsea Centaurium. One of the most beautiful varieties 

 I have met with was of Centaurea uigra, with white rays and a 

 red centre. 



