The answer appears on the seventy-fifth page of the book.

Of creation there are two grand divisions, organized and inorganized. Of the organized there are two divisions, called the animal and vegetable kingdoms. These two, with inorganized creation, constitute the three great departments of nature, which gradually approach, and almost imperceptibly pass into one another.

[…] for example, Gleitman (1990:30), in support of her claim for universal alignments of syntax and semantics, argues for the universal naturalness of three arguments for 'put' verbs (a putter, a puttee, and a location).

Moreover, sponges possess very high reconstitutive and regenerative abilities up to the re-building of a functional body from dissociated cells […]