ON THE MISSELTOE. 383 



snake not being found in that country. But Radnorsliire, if it owe 

 the exemption of its orcJiards from the parasitic plant to the good 

 offices of any saint, lias been very ungrateful in not preserving 

 some record of his name, since the old "forefathers of the hamlet" 

 content themselves with believing the fact without attempting to 

 account for it. 



It is certainly a most curious and striking fact, that in one 

 locality this parasitic intruder should be found in abundance ; in 

 another and neighbouring spot, apparently, at least in every essen- 

 tial particular, the same, and where trees of the very same kind 

 abound, it should be unknown ; while in a third situation again, 

 very diiferent from either of the preceding, it should grow in the 

 greatest profusion. From the extent of country over which this 

 plant has been noticed to prevail, comprising Scotland, and the 

 North of England on the one hand, and Greece and the South of 

 Europe on the other ; this diversity of distribution as it respects our 

 midland districts, can scarcely be thought to depend upon any pe- 

 culiarities of climate. Can the difficulty be solved by a reference to 

 the geological structure of the country ? In the old red sandstone 

 districts of Herefordshire and Worcestershire, the plant abounds, 

 and even where the upper beds of the grauwacke are indented by 

 breaks of the sandstone. In the grauwacke series generally, but 

 especially the older beds, it is not to be found. The soil is, of course, 

 the disintegration of tlie rocks. Is it probable that a difference of 

 geological formation, and consequent difference of soil may render 

 the vegetable productions fitted or otherwise for the support of 

 parasitic intruders ? It is an incontrovertible fact that many 

 parasitic/i/wyi* and lichens, and others of the lower tribes of vegeta- 

 bles, are found to attach tliemselves to those plants which are, from 

 wliatever cause, in a less vigorous and healthy state ; and it is no 

 less certain that the vigour and health of a plant are materially 

 influenced by the nature of the soil in which it grows. The same 

 has also been remarked in marine plants, and Dr. Greville ob- 

 serves — " It is very clear, and well-known to the practical botanist, 

 that marine plants are much influenced by the nature of the soil, 

 not merely in regard to species, but in luxuriance and rapidity of 

 development; a few yards is, in some instances, sufficient to 

 create a change, and the space of three or four miles, a very 

 striking one. Thus calcareous rocks favour the production of 

 some species, sandstone and basalt that of others ; and it would 

 appear that the soil has an effect even upon those Algce which 

 grow parasitically upon the stems of the larger species."* Whether 

 the soils resulting from the disintegration of the rocks of the 

 grauwacke series are more congenial to the trees than those of the 

 sandstone districts, and render them less liable, therefore, to the 

 attacks of parasites, or whether the reverse is the case, and 

 their juices are not in sufficient luxuriance, both in respect of 

 quantity and quality for the support of so large a parasite as the 



* Grev. Algae Brit. Introduction, p. viii. 



