PINEAL GLAND FUNCTION 



215 



light piece of skin these melanophores are contracted to rough 

 spheres of pigment (fig. 7, Sub. M.). The epidermal melano- 

 phores exhibit an unchanged appearance in both drawings. 

 A sagittal section of normal skin (fig. 5) shows the relation be- 

 tween the tw^o types of melanophores and the various layers 

 of the integument. 



These described alterations in pigmentation are invariably 

 induced in tadpoles upon the administration of pineal materials, 

 be they the fresh minced glands, simple desiccation preparations, 

 or simple aqueous extracts. In an effort to associate these 

 changes with certain constituents of the pineal gland, various 

 fractions of the pineal were prepared and employed and are 

 now about to be described. 



Ep.M. 



Sub.M. 



Fig. 5 Sagittal section of integument taken from the eye region of a normal 

 tadpole. Section illustrates the two types of melanophores and their position 

 relative to the tissue layers. 



ABBREVIATIONS 



Ep., epidermis 



l7it., integument, including epidermic 

 and sub-epidermal tissue 



Ep.M., epidermal melanophores 

 Sub.M., sub-epidermal melanophores 

 B.M., basement membrane 

 Sub., sub-epidermal connective tissue 



Effect of pineal fractions on pigmentation 



In the preparation of these split materials the fresh glands 

 were either ground up and immediately extracted or desiccated 

 and subsequently extracted. From the results of a wide varia- 

 tion in fractionation methods, chief interest centers around 

 the acetone and alcohol extractives and their residues. In the 

 case of acetone the process was carried out in a Soxhlet appara- 

 tus. On freeing the extractives from acetone there resulted 



