Plant-animals, oysters and sponges

Meaning

Oysters, sponges and comparable aquatic beings raise a question about the kind of life they share. The author says they more deserve the name plant-animals than fish, using borderline cases to test a simple division of visible creatures. Plantanimaux names that hybrid classification in the argument, not a modern taxonomic group.

The examples follow claims about hidden seeds and generation without visible parents. Their role is to make the reader inquire into degrees and modes of life rather than assume every aquatic body has the same sensitive and vegetative capacities. The passage’s rhetorical classification does not establish the organisms’ alleged origins or replace the three-kind scheme with a verified biological taxonomy.