20 THE ESSEX NATURALIST for the track itself, we have found no evidence of its survival, even as fragments, yet many footpaths and by-roads follow very closely in its direction. In some cases, it has formed the basis of modern rights-of-way preserving the ancient path in the heart of a modern town. Without a doubt the track was used by pedestrians, and not by wheeled traffic, for it travels in a series of short straight sections with a complete disregard for contours. This is particularly noticeable in the Chiltern country, where it traverses a long series of steep-sided bottoms radiating fanwise from the south-east. Where the land is even and firm, as in west Suffolk, the track runs remarkably direct for as much as ten miles at a stretch, but in parts of Essex, where many low-lying river-valleys must be crossed, it weaves between the sighting-points, yet maintains to an extraordinary degree a constant general direction. In reviewing the course of the track, we shall begin at the most westerly point hitherto traced by us, at Thatcham, near Newbury, Berkshire. We have reason to believe that the site of a Mesolithic workshop floor discovered by Peake and Crawford, in 1920f2],lies upon the track, for a trail of conglomerate boulders pointing to- wards it was found in Holly Wood, according to the Geological Survey, 1867. This trail of five stones lay some two miles north- east of Thatcham, and pointed towards the Thames at Pang- bourne, forming a section of the track which we consider probable but unconfirmed. It is not until we reach Witheridge Hill, near Stoke Row, Oxfordshire, some miles north of the Thames cross- ing, that we meet the connected trail of trackstones leading away across the Chiltern slopes, and passing two other Mesolithic flint-workshop floors at Nettlebed Common and Kimble Farm respectively [3]. Puddingstone boulders have been found at inter- vals, for instance, at Bixbottom Farm, Warmscombe Lane, Kimble Farm, Fingest, and Cadmore End. The eastern slopes of the Bled- low Ridge are crossed at a point opposite Bradenham, where the trackstone lies embedded at the foot of the south-western buttress of the Church tower. This is the first "pagan" stone encountered, and from it the direction follows the line of the road to Walters Ash, passing an unusual feature on the right—an eroded valley strewn with an outcrop of boulders of puddingstone, similar to its sarsen counterparts found on Salisbury Plain west of Shaftesbury. From Bradenham to Great Missenden the line of the track is very well marked, roughly following a series of footpaths liberally punctuated by conglomerate boulders, and rising and falling over the steep ridges and deep bottoms, crossing Piggott Wood, Denner Hill, and Nanfan Wood. At Great Missenden is an extraordinary example of the persistence of the track in a modern right-of-way, preserved as a narrow foot-tunnel under the railway, and an