Figure 1: Photos of a dog embryo and fetus showing the formation of skin appendages. The fore- and hind limb of a 32-day-old embryo are shown in A and B, respectively, with digits but no claws. The formation of claws in the foreand hind limbs of a 44-day-old fetus are shown in C and D, respectively. E, F and G show follicles of tactile hair, mammary glands (arrows) and footpads of the forelimb (asterisks), respectively.