The Pituitary Body in Relation to the Regulation of the Distribution OF Pigment IN Chromatophores . . . 244 IX. New Observations on the Chemistry and Pharmacology OF Extracts of the Pars Neuralis 258 X. The Pars Neuralis as a Gland of Internal Secretion . 274 Appendix. The Structural Formulas and Principal Actions OF Hormones of Natural Origin Bibliography Index 51955 ' Whether or not a pars intermedia can be identified in the bird's pituitary is still undecided (see the discussion of Wislocki and Gelling).f 10]''' Testosterone or androstenedione can cause ovulation by acting on the excised ovary of the toad, X. laevis .