77/r 7< 



Mr Miller Christy first worked out the distribution of the 

 Oxlip, Primula cltit/or, in England '. It occupies two tracts of 

 country, one large roughly dumb-hell-shaped portion lying in 

 South Suffolk, North Essex and South-East Cambridgeshire 

 and North Herts., and another a small circular tract princi- 

 pally in "West Cambridgeshire. These tracts, it should l>c 

 noticed, coincide with the shade association mentioned in this 

 paper. The Oxlip is a semi-shade plant occupying open woods 

 upon boulder clay. Although along the north-west border in 

 Cambridgeshire, stretching from near Bury St Edmunds to 

 Saffron "Walden and beyond, its limit of distribution practi- 

 cally coincides with the limit of the clay, elsewhere it is found 

 always growing within the bounds of this deposit. 



Probably within these areas, certainly within the larger of 

 the two, the Primrose, Primula acaulis, except where planted, 

 is not found; the Cowslip, P. veris, however, as already men- 

 tioned, abounds. Round the outside of the Oxlip areas 

 hybrids occur, both between Primula acmiH* and Primulu 

 elatior and Primula acaulis and Primula veris; elsewhere 

 these are not found, but Primula elatior and Primula /vr/x 

 occur, scattered over these districts, but are always very rare. 



Taking Cambridge as a centre it is easy to trace the north- 

 west limit of the larger Oxlip area. Using the Newmarket 

 line which at Six-mile-bottom rises slowly till it reaches tin- 

 top of the chalk at Dullingham, it is possible, striking south 

 from either of these stations, to quickly gain a yet higher 

 ridge, boulder clay overlying chalk, where at once the woods 

 begin. Along this ridge of hills one can trace the hybrids 

 from copse to copse ; at the end of the Devil's Dyke, m-ar 

 Newmarket to Dullingham, Brinkley, Balsham, and a^ain 

 across the lowland from Hadstock to Saffron Walden. Going, 

 at any point along this boundary, furtlucr south-east the hybrid 

 belt is passed, and copses full only of the pure Oxlip are found. 



To the west of Cambridge the district is much smaller, 

 and here the hybrids are more numerous. 



1 Journ. Limit-ait Soc. Vol. xxxni. 1897, pp. 172201. 



