2 The pigment that accumulates in the cells of the stratum spinosum is a. actin. b. melanin. c. keratin. d. collagen. 3 The protein that accumulates in the dead cells of the stratum corneum is a. actin. b. melanin. c. keratin. d. collagen. In which layer of the epidermis are tactile discs found? a. Stratum corneum. b. Stratum granulosum. c. Stratum basale. d. Stratum lucidum. e. Stratum spinosum..