SCIENTIFIC SUMMARY. 
213 
different gravels — 1st, under the 25-feet contour-line ; 2nd, under tlie 110- 
feet contour-line ; and 3rd, under the 350-feet contour-line — all more or less 
containing marine shells. Although these gravels are of distinct ages, yet 
the fossils collected from them have been lumped together. Then older 
than the Esker gravels (under the 350-feet contour-line), there are gravels 
at about the following respective heights — 550 feet, 750 feet, and 1,200 feet, 
some of which contain fossils ; and although these gravels must he much 
older than the three groups first named, yet their fossils have been all 
classed together. I remember hearing my brother, the late Dr. Kinahan, 
remark that the group of fossils from the gravels at Bohernabreena (about 
200 feet) were distinct from the group found in the gravels at Howth and 
the coast to the northward (under 100 feet). In no place in Ireland have I 
seen gravels belonging to the first three groups (the third being the so- 
called ‘middle gravels’) under normal glacial drift, although I have found 
gravels belonging to all the others so situated.” 
Scotch Fossil Trees . — We learn that six trunks of large trees have been 
obtained at Craigleith quarry since 1826. The largest, 36 feet long and 12 
to 14 feet in girth, has been taken to the British Museum, and is to be set 
up erect there. Another is nearly 30 feet long, and has been removed to 
the Botanic Gardens. The trees were conifers. The surface of each is 
bituminous coal, varying from one-twentieth of an inch in thickness to two 
inches. The trunks inside of this coaly exterior consist of carbonate of 
lime, carbonate of magnesia, carbonate of iron and free carbon in varying 
proportions. The coaly exterior is attributed, by Sir R. Christison, to 
bitumen passing to the surface as the destructive distillation of the wood 
was going on within. 
MEDICAL SCIENCE. 
The Brain in Man and the Lower Animals . — In the “ Proceedings of the 
Royal Society” (No. 163) appears a paper by Prof. Marshall, F.R.S.,in which 
the author says : — “ 1. I desire to communicate to the Royal Society the fact 
that I have, by severing the cerebral hemispheres in certain definite direc- 
tions in man, and also in some of the higher vertebrata, and by then weigh- 
ing the separated portions, not only arrived at some interesting and important 
results as to the relative size of those portions in different animals and in 
man, but I am enabled to state that this method, applied to the brains of 
individuals of different race, sex, age, education, and occupation, seems likely 
to furnish a means of investigating individual peculiarities in the human 
cerebrum. I propose shortly to communicate my results to the Society. 2. 
I have likewise made numerous observations on the convolutions of the 
human brain, wfith the view of explaining their symmetry in certain regions, 
and their asymmetry in others. In endeavouring to trace more particularly 
the causes of the asymmetry of the convolutions which prevails in man, I 
have been led to believe that some, at least, of this is due to the right-hand- 
edness of man. I find, on studying a large number of human cerebra, that 
there are stronger evidences of essential asymmetry, as distinguished from 
