Elementary biology; an introduction to Elementary biology; an introduction to the science of life elementarybiolog00grue Year: 1924 REPRODUCTION IN ANIMALS 329 In some species of toads the fertilized eggs are placed in the mouth of the parent, where they are kept until the tadpoles are large enough to swim away. Among the batrachians, — which include newts and salamanders, as well as frogs and toads, — there are very many cases of parental care of the devel- oping young, ranging all the way from abandonment directly Fig. 156. Sperm cells of animals. (Very highly magnified) /, pig; 2, bird
Elementary biology; an introduction to Elementary biology; an introduction to the science of life elementarybiolog00grue Year: 1924 REPRODUCTION IN ANIMALS 329 In some species of toads the fertilized eggs are placed in the mouth of the parent, where they are kept until the tadpoles are large enough to swim away. Among the batrachians, — which include newts and salamanders, as well as frogs and toads, — there are very many cases of parental care of the devel- oping young, ranging all the way from abandonment directly Fig. 156. Sperm cells of animals. (Very highly magnified) /, pig; 2, bird ; j, salamander ; ^, ray ; j, threadworm {Ascaris) ; 6, lobster after the discharge of the gametes to guarding within the body of the mother until the young are fully formed and able to shift for themselves. 382. Reproduction in the insects. Among the insects, which of all animals are most distinctly adapted to living in the air, the spermatozoa of the male are passed directly into the body of the female through a special duct. The semen is discharged into a receptacle, from which the spermatozoa pass, a few at a time, into another space, wherein the female gametes (the eggs) are fertilized. It is possible for a queen bee to retain a quantity
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