TRANSACTIONS OF SECTION C. 391 
felspars is a promise of the sort of work that may be expected from such 
laboratories. 
I fear it will be only too evident to those who have given me their patience 
during this Address that I approach the problems considered in it from the point 
of view, not of the geologist or the chemist, but of the crystallographer, to whom 
the birth and growth of crystals are a study in themselves. Whether we watch 
with the microscope a tiny crystal growing from a drop of solution, or contemplate 
with the imagination the stages by which the fiery lavas of past geological periods 
sank to rest and crystallised, we view the same process; it is the transformation 
of liquid into crystal. Not necessarily into a solid, for recent research shows that 
there is no dividing line between liquid and solid; a plastic solid body may flow; 
a solid glass is only a supercooled liquid; witness, for example, the experiments of 
Adams on rocks, and of Tamman on supercooled liquids. The real primary distine- 
tion is between crystalline and non-crystalline material, and there is even good 
reason to believe that some crysials are liquid without ceasing to be crystals. 
The properties of most rocks, of metals, alloys, ice, and many other substances 
are due to the fact that they consist of crystals, and the importance of the study of 
the latter is now, I trust, being brought home alike to chemists, physicists, 
geologists, and engineers in connection with problems relating to the strength, 
the movements, the origin and changes of what are usually called solids. 
And so I close, as befits a student and teacher of crystallography, with the 
hope that renewed attention may be paid to this subject, and that it may attract 
the interest of many a keen intellect in South Africa. The higher scientific 
studies are now establishing themselves as an integral part of the educational and 
intellectual life of the country: this is in no small measure due to the South 
African Association ; and we may hope that the visit of the British Association 
will be of some help to her younger sister in the task of diffusing a taste and an 
interest for the pure truths of science and the studies that they both hold dear. 
5 
CAPE TOWN. 
WEDNESDAY, AUGUST 16. 
The following Papers and Reports were read :— 
1. The Geology of Cape Colony. By A. W. Roarrs, M.A. 
2. The Classification of the Karroo Beds of South Africa. 
By R. Broom, M.D., D.Se. 
An attempt is made from the study of fossil remains to give a more satisfac~ 
tory sub-division of the Karroo System than has hitherto been possible. The - 
larger sub-division into the Dwyka, Ecea, Beaufort, and Stormberg Series is 
tentatively retained. 
The Beaufort Series is divided into three parts. "The lowest series is character- 
ised by the presence of Therocephalians and Anomodonts. These lower beds can 
be again sub-divided into an earlier series, in which occur Paretasaurus and Titano- 
suchus, a middle series characterised by the prevalence of Dicynodon and Oudenodon, 
and an upper characterised by the presence of Atstecephalus. 
Above the Lower Beaufort Beds occurs a Middle series, characterised by the 
rarity of reptilian remains other than of Lystrosaurws, which is very abundant. 
The Upper Beaufort Beds are characterised by the presence of the Cynodonts. 
In the earlier sub-division of these upper beds Procolophon is the most charac- 
teristic fossil, and in the upper the Cynodont Cynognathus. 
The Stormberg Beds appear to be divisible into two groups—a lower, the 
