Beer had, however, devoted most of his own efforts to systems composed from sim-
pler organisms: colonies of Daphnia, a freshwater crustacean (Pask had considered mosquito larvae), of Euglena protozoa, and an entire pond ecosystem (Fig. 6):
[P]ure cultures . . . are not, perhaps, ecologically stable systems. Dr. Gilbert, who had been trying to improve the Euglena cultures, suggested a potent thought. Why not use an entire ecological system, such as a pond? . . . Accordingly, over the past year, I have been conducting experiments with a large tank or pond. The contents of the tank were randomly sampled from ponds in Derbyshire and Surrey. Currently there are a few of the usual creatures visible to the naked eye (Hydra, Cyclops, Daphnia, and a leech); microscopically there is the expected multitude of micro-organisms. The state of this research at the moment is that I tinker with this tank from time to time in the middle of the night.

Some clarification might be needed here. The key point is that all the systems Beer talked about are adaptive systems, capable of reconfiguring themselves in the face of environmental transformations. In a steady state, an ecosystem like a pond, for exam- ple, exists in a state of dynamic equilibrium with its environment, homeostatically responding to fluctuations that threaten its viability. And if the environment changes, the ecosystem will reconfigure itself to achieve a dynamic equilibrium with that, just like Ashby’s electromechanical homeostats. Beer’s idea was that if one could only couple such an adaptive system to a factory, say, making the factory part of the pond’s environment, and vice versa, the health of each could be made to hinge on that of the other, in a process that Beer called reciprocal vetoing. Disturbances from the factory might trip the ecosystem into a new configuration, which would in turn perturb the operation of the factory, and if the factory in its new state was still unstable, new disturbances would travel back to the ecosystem—and so on until the pond and the factory achieved a collective state of dynamic equilibrium with each other and their outside environments. This is the way in which a pond with some small organisms and a leech could serve as an adaptive brain for the automatic factory. An amazing idea, though I can see no reason in principle why it should not work.

Having said that, of course, there are not, at the moment, any such biological com- puters. As I hinted already, this project came to naught. The immediate technological problem lay in achieving a coupling between naturally adaptive systems and the sys- tems they were intended to control. From the schematic of the automatic factory it is clear that Beer had analysed what the key input and output variables were. The prob- lem was to make biological systems care about them. How could they be translated into variables that would impinge significantly on a biological controller? In his 1962 review Beer mentioned a couple of attempts to do this, and indicated where difficulties had arisen (1962b, p. 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.
To put it another way, having consumed the iron filings, the Daphnia excreted them and the water filled with rust. Another attempt hinged on the fact that Euglena are sensitive to light, and Beer sought to achieve optical couplings to a tank full of them. ‘However, the culturing difficulties proved enormous. Euglena showed a distressing tendency to lie doggo, and attempts to isolate a more motile strain failed’ (Fig. 7).