STAF FORD BEER - The Cybernetic Brain - page 233

Figure 6.8. The euglena homeostat. square, euglena culture, with tropism displayed
as shown; solid diamond, stimulus; circle, sensory receptor; hatched triangle,
inhibiting influence, and, open triangle, stimulating influence, of a 's sensation on
b 's stimulus. Source: Beer 1994a, 30, fig. 2.
Beer had, however, devoted most of his own efforts to systems composed from
simpler organisms: colonies of Daphnia , a freshwater crustacean (Pask had
considered Aedes aegypti , the larva of the yellow fever mosquito), of Euglena
protozoa, and an entire pond ecosystem. The key question with all three sys-
tems was how to interest these biological entities in us, how to couple them
to our concerns, how to make a U-machine that would respond to and care
about the state of the cybernetic factory. And this coupling was where Beer's
attempts foundered (1962b, 29):
Many experiments were made with [ Daphnia ]. Iron filings were included with
dead leaves in the tank of Daphnia , which ingested sufficient of the former to
respond to a magnetic field. Attempts were made to feed inputs to the colony
of Daphnia by transducing environmental variables into electromagnets, while
the outputs were the consequential changes in the electrical characteristics of
the phase space produced by the adaptive behaviour of the colony. . . . However,
there were many experimental problems. The most serious of these was the col-
lapse of any incipient organization—apparently due to the steadily increasing
suspension of tiny permanent magnets in the water.
Euglena are sensitive to light (and other disturbances) in interesting ways, and
Beer sought to achieve optical couplings to a tank full of them “using a point
source of light as the stimulus, and a photocell [to measure the absorption of
light by the colony] as the sensory receptor” (fig. 6.8).