ENDOCRINE GLANDS 



207 



(p. 260) and there may be a melanophore-concentrating one in the 

 anterior lobe. Oxytocin and vasopressin are present but there is no 

 evidence that excretion is controlled by the pituitary. 



The thyroid tissue is not aggregated into a compact gland but forms 

 scattered masses along the ventral aorta. Its hormones appear to be 



ns.a. 



Fig. 126. Urohypophysis of A, eel; b, loach (Misgurnus); c, the same in a loach 



after sectioning the spinal cord and injecting hypertonic saline. 



b. blood-vessels; ep. ependyma;//. filum terminate; /;/. lumps of secretion (? 'Herring bodies'); 



tie. nerve endings; ns.a. neurosecretory axon; ns.c. neurosecretory cells; s.d. storage depot of 



neurosecretion. (After F.nami, N., in Symposium on Comparative Endocrinology. Wiley, New 



York.) 



identical with those of mammals, including mono- and di-iodotyrosine 

 and thyroxin. Thyroid follicles are often found in the kidneys, heart, 

 eye, and elsewhere in the body of fishes, especially those deprived of 

 iodine. 



The suprarenal and interrenal tissues are partly associated in masses 

 around the thickened walls of the posterior cardinal veins. Because of 

 the difficulty of isolating these tissues there is little information as to 

 their function. The corpuscles of Stannius are groups of gland cells 

 dorsal to the kidnevs, they have been held to be related to the adrenals, 

 but their nature is still uncertain. 



