DISAPPEARANCE OF THE PIGMENT IN THE MELANOPHORE 

 OF PHILIPPINE HOUSE LIZARDS ^ 



By Edward S. Ruth and Robert B. Gibson 



{From the Departments of Anatomy and of Physiology, College of Medicine 



and Surgery, University of the Philippines) 



TWO COLORED PLATES 



The literature that has accumulated on the subject of mela- 

 nophores and chromatophores or pigment-carrying cells is abun- 

 dant and is chiefly concerned with a discussion of their origin, 

 morphology, and movements (Eycleshymer,(2) Laurens, (6) 

 Spaeth, (10) Lieben,(7) Ballowitz,(i) Hooker, (3) and others). 

 However, the study of the pigment granule, its elaboration, 

 migration, and destruction, has received but comparatively little 

 attention (Von Szily,(ii) Redfield,(8) Hooker, (4) and others). 



An analysis of the literature indicates that there are at least 

 three different morphological types of melanophores, which 

 Laurens (5) reviews at some length. 



Ballowitz * * * reiterates his many times expressed opinion that 

 the movements of the pigment in the pigment cells are due to intracellular 

 streaming in the chromatophores which have unchangeable cell forms. The 

 protoplasm of the chromatophores is filled with numerous extremely fine, 

 radially arranged, anastomosing canals in which the pigment is contained, 

 and which are closed on the outside. No membrane can be demonstrated, 

 but the walls of the canals are extremely thin and are formed by the pro- 

 toplasm of the chromatophore. The contraction of the protoplasmic walls 

 of the canals, alternating with its relaxation moves and drives forward 

 the pigment granules. If the protoplasmic wall in the processes of the 

 cells contracts in transverse waves from the periphery toward the center, 

 then the pigment streams toward the center of the cell, and the canal 

 protoplasm of the center of the cell disk at the same time relaxing, the 

 pigment streams into it and rounds it off. On the other hand, if the central 

 protoplasm contracts, and the protoplasm of the process relaxes then the 

 melanin granules stream out into the processes. 



Spaeth holds to the theory, which is perhaps the most popular, that 

 the chromatophores of fishes are fixed stellate cells within which the 

 pigment is carried in a rather fluid cytoplasm, streams into and out of 

 the processes during expansion and contraction. 



Hooker - upholds another and third view, that the melanophores of 

 Amphibia * * * lie in preformed spaces and that they expand and 

 contract within the spaces which enclose them. The acts of expansion and 



• Received for publication January, 15th 1917. 



■ See Hooker, reference No. 3. Igl 



