On this latter view we may regard the tusks of the male babirusa as examples of redundant development, analogous to that of the single pair of lower teeth in some of the beaked whales.
The zoospore is usually a pyriform mass of naked protoplasm, the beaked end of which where the cilia arise is devoid of colouring matter.
Thus, although isogamy consists in typical cases of a union of naked motile gametes by a fusion which begins at the beaked ends, and results in the formation of an immotile spherical zygote surrounded by a cell-wall, in Leptosira it is noticeable that the fusion begins at the blunt end; in a species of Chlamydomonas the two gametes are each included in a cell-wall before fusion; and in many cases the zygote retains for some time its motility with the double number of cilia.
The pigmy whale (Neobalaena marginata), for instance, has only been met with in the seas round Australia, New Zealand and South America, while a beaked whale (Berardius arnouxi) appears to be confined to the New Zealand seas.
This is a large seed, with a very long micropyle; it has a beaked pollen-chamber, and a complex integument made up of hard and fleshy layers, closely resembling the seed of a modern Cycad; the nucellus, however, was free from the integument, each a sketch after Kidston.