An empty wine glass is filled with water from a jug. Some strands of hay are added with tweezers. Dark ground microcinematography of infusoria. A screen-filling shot of the eye of a needle with infusoria. Varieties are introduced in microcinematographic shots and commentary: barrell animalcules, slippers, 'purse infusoria' feeding and in close-up, showing the mouth. Purse infusoria divide into two. Trumpet infusoria attach themselves to hay. 'Bells' do the same, but are also able to detach themselves. 'Bells' are consumed by another creature. Variety of 'bell' infusoria with 'spring' attachments to hay. An animated sequence explains the reproduction of the 'bell' infusoria via two different mechanisms. The life cycle of the new individual is then followed in animation. The film reverts to microcinematography to describe colonies of 'bells' on single stalks, 'like white heather'. Final shot of wineglass alive with infusoria.