The comparative richness of proteaceous plants in Western Australia and South Africa first suggested a common source for these primitive types.
At all stages of religious development, however, and more especially in the case of the more primitive types of cult, prayer as thus understood occurs together with, and shades off into, other varieties of observance that bear obvious marks of belonging to the same family.
- Appendages of the 2nd and 3rd pairs retained and developed, as in the more primitive types of Nymphonomorpha; but those of the 1st pair are either rudimentary, as in the Ascorhynchidae, or atrophied, as in the Colossendeidae.
It was early perceived by Huxley, Cope and many others that Cuvier's broad belief in a universal progression was erroneous, and there developed the distinction between " persistent primitive types " (Huxley) and " progressive types."
"The antlers of young deer are in the form of simple spikes; and this form is retained in the South American brockets, although the simple antlers of these deer appear due to degeneration, and are not primitive types.