[Walter even gave the tortoises a mock-biological name, Machina speculatrix] because they illustrate particularly the exploratory, speculative behavior that is so characteristic of most animals.

p. 43 as cited in: Owen Holland (2003) "The first biologically inspired robots" - An imitation of life (1950)

https://robotics.cs.tamu.edu/dshell/cs689/papers/h...[robotics.cs.tamu.edu]