From MICHAEL COTTERILL
Recently, Stephen Young showed in ‘How plants fight back’ (1 June) that
whereas lowlier aquatic animals like hydra do have green symbiotic algae,
there are no green herbivorous mammals or other terrestrial animals because
they have such a small surface area compared with that of plant-leaves that
they could never photosynthesise a square meal.
Michael Cotterill Freshwater, Isle of Wight
