# Mr. Croll — The Origin of Species character guide

> Mr. Croll in The Origin of Species by Charles Darwin.

**Role:** minor

**Also known as:** Mr. Croll

**First appearance:** 0089-dispersal-during-the-glacial-period

## Who they are

A geologist who proposed astronomical causes for glacial periods.

## In the story

### [On the Imperfection of the Geological Record](https://www.betterreads.dev/discover/the_origin_of_species_se/chapters/x-on-the-imperfection-of-the-geological-record)

Mentioned among those who studied subaerial degradation as a major geological agency.

### [On the Lapse of Time, as Inferred from the Rate of Deposition and Extent of Denudation](https://www.betterreads.dev/discover/the_origin_of_species_se/chapters/on-the-lapse-of-time-as-inferred-from-the-rate-of-deposition-and-extent-of-denudation)

His calculations on denudation rates and illustration of a million years are used to convey the scale of time.

### [On the Sudden Appearance of Groups of Allied Species in the Lowest Known Fossiliferous Strata](https://www.betterreads.dev/discover/the_origin_of_species_se/chapters/on-the-sudden-appearance-of-groups-of-allied-species-in-the-lowest-known-fossiliferous-strata)

Estimated about sixty million years since the Cambrian period.

### [Alternate Glacial Periods in the North and South](https://www.betterreads.dev/discover/the_origin_of_species_se/chapters/alternate-glacial-periods-in-the-north-and-south)

His memoirs on the eccentricity of the earth's orbit and its influence on oceanic currents and glacial periods are central to the chapter's argument.

## Links

- HTML: https://www.betterreads.dev/discover/the_origin_of_species_se/characters/croll
- Book: https://www.betterreads.dev/discover/the_origin_of_species_se
- All characters: https://www.betterreads.dev/discover/the_origin_of_species_se/characters