KEPOKTS OE SOCIETIES. 
191 
vitis-Idcca in flower, on Charnwood Forest, a plant never yet recorded 
in this county. Rev. T. A. Preston, M.A., opened a discussion on the 
zero temperature of vegetation. He said it was now an accepted 
doctrine that about 42° Fahr. was the temperature below which vege¬ 
table growth could not take place ; that as soon as the temperature 
rose above that point cell-formation began; that the amount of growth 
depended mainly upon the length of time during which a plant was 
exposed to such higher temperature, and the total number of degrees 
above 42 by which it was affected during that time ; and that different 
plants required different numbers of such degrees to bring them 
to maturity. He was not himself quite satisfied with this theory. 
He had collected and recorded phenological observations for a long 
series of years, and he thought the theory would require some modi¬ 
fication. The discussion was continued for some time. The Rev. T. 
A. Preston then read a short paper on “ Garduus tuberosus , a rare 
British Thistle,” which was illustrated by a number of dried speci¬ 
mens of this species and of its nearest allies, C. pratensis and G. acaulis. 
This thistle appeared only to exist in England in the county of Wilts, 
and the early records of its appearance there were curiously incon¬ 
sistent. It now grew at Avebury, and, possibly, in one or two other 
localities. Some supposed it to be a hybrid between pratensis and 
acaulis. It had the habits of the first, and the divided and serrated 
leaves of the second, but was distinguished by the fusiform tubers of 
the root. 
. CARADOC FIELD CLUB (SHROPSHIRE).—The first meeting 
of the season was held on Friday, May 27tli, in conjunction with the 
Severn Valley Club. The locality chosen was Wenlock Edge, and the 
special point of rendezvous was Larden Ditches, a large encampment, 
probably of British origin, and still showing a triple entrenchment. 
On their route the members of the party paid a visit to no less than three 
fine specimens of sixteenth century manor houses—Wilderhope, the 
ancient seat of the Smalman family, and Shipton and Larden Halls, 
which belonged respectively to the Myttons and the Mores, and are 
now both the property of Mr. Jasper More, M.P., who, in company 
with Sir Charles Rouse Boughton, kindly acted as guides on the 
occasion. The characteristic geology of the neighbourhood was 
pointed out by the Rev. J. D. La Touche, the president of the 
Caradoc Club, and several exposures of Upper Ludlow Shale 
furnished many characteristic fossils. A few plants of some rarity 
were found, but the day was marred by a succession of cold showers, 
which were more favourable to the development of mud than the 
pursuit of science. 
DUDLEY AND MIDLAND GEOLOGICAL AND SCIENTIFIC 
SOCIETY.—This Society held their second meeting for this season on 
Tuesday, 14th June, at the Abberley Hills. The party, consisting of 
upwards of thirty members and friends, with Mr. H. Pearce, F.G.S., 
president, drove from Kidderminster to Witley, and were conducted 
through Witley Court and grounds by Canon Melville. They then 
visited an interesting outlier of Wenlock Limestone in the grounds of 
Abberley Hall, where a number of fossils were found, among which 
may be mentioned lleliolites Murchisoni , Favosites Forbesi , F. Gotli- 
landica , Monticulipora , Cyathopliyllum, llhynchonella cuneata, Stropho- 
mena rhomboidalis , Ac. The party then walked to a quarry of 
