When humans attempt to colonize an alien planet, the native creatures quickly evolve competitive forms.
| Date | Publication | Publisher | Type | Page | |
|---|---|---|---|---|---|
| March 1953 |
|
Galaxy Science Fiction, March 1953 | Galaxy Publishing Corporation | MAGAZINE | 78 |
| November 1953 |
|
Crossroads in Time | Permabooks | Anthology | 143 |
| April 1954 |
|
Second Galaxy Reader of Science Fiction | Crown Publishers | Anthology | 281 |
| 1966 |
|
Spectrum V | Gollancz | Anthology | 13 |
| 1967 |
|
Spectrum V | Harcourt, Brace & World | Anthology | 13 |
| September 1967 |
|
Spectrum V | The Science Fiction Book Club (UK) | Anthology | 13 |
| August 1968 |
|
Spectrum 5 | Berkley Medallion | Anthology | 15 |
| November 1968 | Spectrum V | Harcourt, Brace & World | Anthology | 13 | |
| 1969 |
|
Spectrum V | Pan Books | Anthology | 15 |
| October 1969 |
|
Spectrum V | Harcourt, Brace & World | Anthology | 13 |
| 1972 |
|
Spectrum 5 | Pan Books | Anthology | 15 |
| 1983 |
|
The Golden Age of Science Fiction | Penguin Books | Anthology | 284 |
| March 2010 | Student Body | Project Gutenberg | Chapbook | ||
| November 2014 |
|
The Eleventh Golden Age of Science Fiction Megapack | Wildside Press | Collection | |
| July 2016 |
|
The Big Book of Science Fiction: The Ultimate Collection | Vintage Crime / Black Lizard / Vintage Books | Anthology | 514 |
| July 2016 |
|
The Big Book of Science Fiction: The Ultimate Collection | Vintage Crime / Black Lizard / Vintage Books | Anthology | |48 |
| July 2016 |
|
The Big Book of Science Fiction: The Ultimate Collection | Vintage Crime/Black Lizard / SFBC | Anthology | 514 |
| March 2019 |
|
The 14th Science Fiction Megapack | Wildside Press | Anthology |