Consciousness and the capability of will and thought are probably wanting in all Protista.
But this definition could not be made so as to apply to many of the Protista.
Most of Protista are so small that they can scarcely, if at all, be perceived with the naked eye.
In this respect some Protista are more like plants, others more like animals.
It is of little moment, practically, where these Protista forms are placed.
Among certain infusoria and other Protista, they do, in fact, remain together and build up branching colonies.
These contradictions 48 are not altogether caused by our imperfect knowledge of the Protista, but in reality by their true nature.
Symbiosis is found among the Protista, being very wide-spread among the radiolaria.
All the fundamental forms of the pro-morphological system, which are of a low rank in that system, prevail in the Protista.
By this means our kingdom of Protista would be considerably increased.
Protista Pro·tis·ta (prō-tĭs'tə)
A former taxonomic kingdom made up of eukaryotic, unicellular organisms. Members of Protista now belong to the kingdom Protoctista, a new classification in most modern taxonomic systems.