118 TRANSACTIONS OF THE PLYMOUTH INSTITUTION. 
schist which characterises the locality, others have been converted 
into true serpentine, and others again into a rock of intermediate 
character." 
Mr. Collins reiterated his views in a continuation of the paper 
published in the Geological Magazine for August, 1886. 
During the summer of 1886, Mr. J. J. H. Teall, author of 
British Petrography, spent many weeks at the Lizard examining 
and photographing the junctions and rocks of that district. The 
Geological Magazine for November of that year, contained a paper 
by him on " The Lizard Gabbros," with a beautifully worked 
plate representing the schistose augen-gabbro of Karakclews in 
Kennack Bay. He contended in this paper that the foliated 
structure in the gabbros is "a secondary structure, due to earth- 
movements acting upon the solid rock," and is the " result of 
pressure, or regional, metamorphism." He considered " that the 
replacement of felspar and diallage by saussurite and hornblende, 
has been largely determined by the same agency." He read a 
paper on 6 'The Metamorphosis of Basic Igneous Rocks" before 
the Geological Association in April, 1887, and a paper on "The 
Origin of Banded Gneisses" at the British Association in Sep- 
tember, 1887. In both of these papers he referred to the Lizard 
rocks. In the former he writes: "The south-western portion of 
the Lizard district is a region of intense mechanical metamor- 
phism. The structural characters of the rocks are similar in 
many respects to those which may be observed along the great 
line of disturbance on the north-west of Scotland;" and after 
referring to Dr. Lehmann's work on "The Origin of Crystalline 
Schists," he said, "Must we regard all hornblende-schists as the 
result of regional metamorphism operating upon basic igneous 
rocks ? So far as these questions are concerned I will confess at 
once that I have not made up my mind." The latter paper, which 
appeared in the Geological Magazine for November, 1887, and was 
accompanied by maps, photographs, and diagrams, concluded with 
the conviction "that a banded structure in rocks (as in the Lizard 
' granulitic group ') having the composition of igneous rocks, was 
no proof that the latter were not of igneous origin." 
With reference to the outlying Lizard rocks he writes : "Accord- 
ing to my views, the rocks of the Lizard Head are structurally the 
equivalents of the schists which occur immediately east of the 
great plain of disturbance in Sutherland. ... I doubt very 
