342 THE DUCTLESS GLANDS 



or cylindrical, with one, two, or more nuclei, and a granular, 

 at times pigmented, cell protoplasm. From the protoplasm 

 stretches a long, thin homogeneous fibre, which is sharply 

 contoured, like an elastic fibre. These cells are young forms 

 of ependyma cells the ' ' radial cells ' ' of Retzius. In addition, 

 there are " protoplasmic cells " which are multipolar, and 

 send out fine glia fibres. There are also " spindle cells," 

 " giant glia cells," " keratin cells," etc. All these build up a 

 primitive neuroglia. 



One of the most interesting features of the posterior lobe 

 is the pigment, which has been known for a long time. Accord- 

 ing to Kohn, the pigment is contained within the threads of 

 the neuroglia, and distends them here and there. When 

 unstained, the substance is of a greenish-yellow tinge, and 

 consists of closely packed, irregular clumps. The amount 

 of the pigment is found to become notably increased in age 

 and disease. For this reason it is supposed to represent some 

 kind of breakdown product. It has been suggested that the 

 pigment bears some relation to the functions of the organ, 

 and especially to the secretion of the anterior lobe. 



Clunet and Jonnesco have also given an account of the 

 pigment in the neurohypophysis. According to these authors, 

 the substance does not give the iron reaction. It is insoluble 

 in alcohol, xylol, benzol, cedar oil, chloroform, and ether. 

 It is stained red with osmic acid, red also with Sudan and 

 Scharlach red, while it is blackened with iron hsematoxylin. 



Haberfeld finds in the human subject at all ages a " pharyn- 

 geal pituitary" a solid string of cells about 5 millimetres 

 long, which runs from below upwards and backwards imme- 

 diately behind the vomer. It contains cells like those in the 

 pituitary itself, but here the chromophobe elements pre- 

 dominate, and the basophiles may be absent. Histologically 

 it resembles the pars intermedia. It is the origin of most of 

 the pituitary tumours. This structure is probably the remains 

 of the original pituitary duct. 



Haberfeld describes a cystic structure in intrauterine life, 

 which is made up of glia cells and fibres, and possessing lumina, 

 surrounded by ependyma cells. This body is frequently, 

 he alleges, the starting-point of gliosarcomata. 



Staderini gives an account of the " eminentia saccularis " 

 (an elevation on the base of the brain immediately behind the 



