United States or Luxembourg ? Vote for the TOP Country of the Week !
As regards the remaining organs of the Amphioxus, we need only mention that the gonads or sexual glands are developed very late, immediately out of the inner cell-layer of the body-cavity. For the rest, the subsequent development into the adult Amphioxus of the larva we have followed is so simple that we need not go further into it here.
Their vegetative functions are accomplished by the simple visceral layer, and their animal functions by the simple cutaneous layer. In these cases the simple cell-layer of the ectoderm is at once skin, locomotive apparatus, and nervous system. Epidermic cells of a human embryo of two months.
Word Of The Day