88 THE LIML. 



visitor makes his 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 grandifolia, 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 ; the general outline, 

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



