84 TRANSACTIONS OF THE © [ Sess. LXXIV. 
(16) E. S. MarsHatt.—L.c. (1898), 73-82. 
(17) C. E. Satmon.—L.c. (1906), 224-227. 
(18) M‘Laren.—On some British Carices.—Bot. Gaz., iii. (1851), 
17-27. 
(19) PrirestLEy.—On Carex.—Trans. Bot. Edin., iv. (1853), 71. 
(20) ANDERSSON, N. J.—Cyperacee Scandinavie, 1849. 
(21) Ricater.—Plante Europee, i., 1890.—Carex, pp. 145-171. 
(22) ASCHERSON and GRAEBNER.—Syn. Fl. Mitteleurop.—Flora Carez, 
v. 264, 1902-3. Index, 1-33, 1904. 
A very full Bibliography of Carex will be found at 
pp. 154-157 (1753-1886) in Mr. Bailey’s No. 3 Paper. 
NOTE ON THE RELATIONSHIPS OF PRIMULA ELATIOR AND 
P. VULGARIS_TO Sort ConpiTions. By R. S. ADAMSON, 
M.A., B.Sc. 
The observations contained in this paper do not in any 
way profess to be complete. They are the result of some 
investigations in a few areas of more or less natural 
woodland in Cambridgeshire, and more especially in 
Gamlingay Wood, on the borders of the counties of 
Cambridge and Huntingdon. 
In this district at the present time P. elatior is confined 
to woods of the Ash-Oak type on Boulder Clay. It does 
not occur at all in the damp meadows, where it is so 
frequent in its Continental localities. 
The Boulder Clay in Cambridgeshire is for the most part 
a very heavy fine-grained clay, with few stones and very 
little sand or gravel intermixed. ‘The lime percentage is 
somewhat variable, but on the whole it is a distinctly 
calcareous soil. For agricultural soils Foreman? gives the 
lime content as varying from 1 per cent. to 57 per cent., 
but in the woods it seems to be rather higher, sometimes 
reaching 7-08 per cent., with an average of about 4 per cent. 
This difference is probably due to the greater amount of 
leaching out that occurs in the soils of cultivated land. 
Locally the Boulder Clay has a different texture—much 
more sandy. This loamy part is much less calcareous, the 
lime content averaging about ‘8 per cent. 
The water-holding powers of these two soils are very 
different. In the woods both become almost or quite 
saturated in the winter. The clay, in fact, is often super- 
1 “Journ. Agric. Sci.,” 1i., 1907. 
