The two living species are distinguishable at a glance.
Jickeli (28) that the species are distinguishable by the characters of their nematocysts.
(So far as the characters of the trophosome are concerned, the seven preceding families are scarcely distinguishable, and they form After E.
In fact, while holding firmly by the former, Bonnet more or less modified the latter in his later writings, and, at length, he admits that a " germ " need not be an actual miniature of the organism, hut that it may be merely an " original preformation " capable of producing the latter.4 But, thus defined, the germ is neither more nor less than the "particula genitalis" of Aristotle, or the "primordium vegetale" or " ovum " of Harvey; and the " evolution " of such a germ would not be distinguishable from " epigenesis."
Chromatophores.The chromatophores or plastids are protoplasmic structures, denser than the cytoplasm, and easily distinguishable from it by their color or greater refractive power.