538 Rev. P. B. Brodie—Kocene Tertiary Insects. 
Chlorite loses water even at a red heat, a clear proof that the affinity 
between the water and the other constituents of the mineral is not 
very strong. The temperature of metamorphism in the Malvern 
rocks often rose to the point of fusion in the shear-zones, and, if 
in other respects the environment of the chlorite were such as 
tended to change it into biotite, there would seem to be no theoretical 
objection to the expulsion of the combined water. 
The decomposition of biotite (or hornblende) into chlorite is of 
course a very familiar fact, and, if the two minerals are found in the 
same rock with an apparent passage between them, it is natural that 
those who have not studied the evidence furnished by the Malvern 
rocks should adopt an old and well known explanation of the 
phenomena in preference to a new and seemingly improbable one. 
Jt seems easier to believe in a decomposition than in a reconstruction. 
We must, however, follow whither the facts lead us. The reason why 
in the Malvern rocks we have sometimes a decomposition of horn- 
blende into chlorite, and sometimes a change of chlorite into biotite, 
is found in the difference of environment. Where the rock is slightly 
crushed, and there are no signs of rock-fusion, there is decomposition 
of hornblende; but where there is intense crushing and shearing, 
accompanied by a high temperature, reconstruction sets in and biotite 
is generated. - 
In the three papers which I have submitted to the Geologica 
Society on Rock-metamorphism at Malvern, I have embodied the 
results of several years of careful work. If any parts of my 
argument are weak or mistaken, I respectfully ask that the defects 
may be pointed out. 
III. — Norges on tHe Eocene Tertiary Insects oF THE IsLE 
or WIGHT. 
By the Rev. P. B. Bropiz, M.A., F.G.S. 
HERE are some points of special interest with reference to the 
Insect remains from the Bembridge Limestone, near Cowes, 
which seem to be worth recording. My friend Mr. Scudder, who 
has done so much to promote the study and elucidate the history of 
fossil insects, and who is our highest authority upon the subject, 
remarks in one of his papers in the United States Bulletin, that in 
no case had he observed the interior of any insect in a fossil state, 
and that the internal structure could hardly be expected to be 
detected. As arule, no doubt, this is perfectly correct, and I have 
never noticed any insect relic either in the Purbecks or Lias which 
showed any portion of the interior, and I am not aware that any 
foreign fossils of a similar class where they occur have done so. 
But the Articulata of the Isle of Wight Tertiaries are certainly a 
remarkable exception. J have lately carefully examined a large 
number of specimens in my collection with a powerful lens, and in 
the majority of cases the insects, mostly of small size, have the 
interior of their bodies exposed, among which, as in other Tertiary 
deposits, ants, which chiefly belong to the Formicidz, predominate ; 
