138 
Mkn. 31, 1910, The Queensland Naturalist. 
formation of new species. Yet this Chalk is divisible 
into well-defined zones, each characterized by its own 
peculiar species. The zones do not merge into each other ; 
the new species come on abruptly above a horizontal line 
not six inches thick. And this holds true from Denmark 
to the Crimea. 
25. — Take another case from argillaceous rocks. Our 
Lias derives its name from the “ layers ” of its mud or 
clay. These are sometimes so fine as to be called paper 
shales. They are paper-thin illustrated plates, often so 
crowded with fossils that not a tenth of a square inch is 
unadorned. They have been laid down quite gently tide by 
tide till the separate divisions of the Lias are each a hundred 
and more feet thick, and one layer is absolutely a replica 
of another. Here we have proof positive of continuity 
of deposition and unchanged physical and climatic con- 
ditions. Yet these Lias strata are as severely divisible 
into zones as the Chalk. One form of Ammonite, for 
example, goes up to one page of the great volume and stops 
there, while another and quite new form comes on a 
hundredth of an inch above. Follow the Lias for hundreds 
of miles, and these zones do not vary. Where is the room 
for Darwin’s great interval to allow of specific change 1 
26. — If you say the Chalk and the Lias each represent 
a long period of time, and so there was time for the 
change, I answer yes, between the top and bottom of the 
formation, but not in the knife-edge interval between the 
zones. 
27. — But I will take a thin bed, the Gault. It was 
laid down in a pretty extensive sea spreading over 
eastern England and western Europe. In England it is 
seldom over 100 feet thick, often much less. Yet it is quite 
distinctly divisible into no less than eleven zones, each 
marked by its own peculiar s])ecies that neither began 
in the beds below nor lived into those above. Where is 
the requisite time to be found here ? 
28. — Allow me to use an analogy from light. Every 
living, every extinct species, must be connected backwards 
in time to the parent form by infinitesimal gradations, 
since the crux of Darwinism is that Natura non fecit per 
saltum. The line of descent must be like a continuous 
spectrum — a rainbow shading imperceptibly from the 
red to the violet. Cut out any large segment — or uncon- 
formity — and you only cause a gap ; the remaining portions 
still are absolutely continuous. 
29. — But this is exactly what we do not find. We 
have no bits of shaded ribbon. We have fairly clear cut 
lines. We get a spectrum of bright or dark lines, like that 
of the Sun’s corona or photosphere, and never in 
