172 Foliation and Sedimentation — Laivson. 
states that ''the foliated structure as everyone knows follows 
closely the planes of the original bedding." 
This again is a rule to which there are very numerous and 
important exceptions, and many dykes and other masses of un- 
bedded rocks have been shown to possess an eminently schistose 
structure. Both in bedded rocks and in dykes the planes of 
schistosity may make any angle with the strike although they 
are commonly parallel to it. 
3. Prof. W. says: "The gneisses and crystalline schists are 
cognate in composition as well as in structure." 
This is true of some gneisses, so-called in the indiscriminate 
application of this word, but not true of the granite gneiss of 
the Lake of the Woods, or of most of the Laurentian gneiss of 
Central Canada which I have seen, except in some cases, in 
which, as any rock may be, they appear to have been sheared 
and rendered schistose over and above any foliation they may 
have had originally. * Then their structure may be said to be 
"cognate" with that of some schists. I cannot regard the horn- 
blende schists which prevail at the base of the Keewatin as 
"cognate" in composition with the granite gneiss of the Lauren- 
tian except in the very wide sense that all rocks are cognate 
in composition, 
4. Prof. W. says: "If the gneisses possessed a very different 
mineralogical constitution, that would not forbid the reference 
of their parallel planes of metamorphism to similar causes." 
This proposition as it stands is quite incomprehensible and I 
cannot therefore discuss it. 
5. Prof. W. says: "It seems eminently improbable that the 
gneissic beds intercalated in the schists should be of the nature 
of dykes." 
I am sorry for this eminently improbable aspect of things, 
but it is an aspect which many truths have when they are first 
considered, and one for which in this particular case I cannot 
hold myself responsible. 
The intrusive or injected character of the gneiss at the con- 
tact with the schists is proved conclusively by the field evidence 
stated and figured on p. 76. Figs. 10 and 11 are not weakened 
by an exclamation mark, or by a page of them. Preconceived 
notions of improbability are but poor arguments to array against 
explicit facts. All the evidence whereby an igneous rock of any 
