88 THE LIME. 



visitor makes Ms way towards Bristol Cathedral. 

 In the woods, however, occurs, and in some parts of 

 England very abundantly, a form of this tree with 

 smaller and thicker leaves, the green of which is at 

 the same time darker, and which is usually distin- 

 guished by authors as the Tilia parvifolia, the lime 

 of the park and garden bearing the name of Tilia 

 Europcea. In gardens and arboretums is likewise 

 met with a third form, technically distinguished as 

 the Tilia grandi folia, the leaves being larger, and 

 pale and downy upon the under- surface. Whether 

 these three forms be distinct " species," let those 

 pronounce who can define what a species is. It is 

 sufficient for all ordinary and useful purposes to 

 regard them as strongly-accentuated utterances of a 

 single idea, and with this understanding alone is it 

 correct, perhaps, to speak of the Europcea as a native 

 of our own island. In any case, the Europcea has 

 been in England so long as now to have become 

 perfectly naturalised; and the grandifolia, though 

 far less abundant, and at present still possessing the 

 aspect of a guest, will no doubt become so likewise 

 in the course of another century. Centuries, though 

 they express a great, deal in the history of human 

 life, simply mark spacious periods in the chronology 

 of trees. All three forms correspond pretty nearly 

 in general figure. The tree is symmetrical, with a 

 solid but rather short trunk j the general outline, 

 viewing it from a distance, is roundish or ovoid, and, 



