TECHNICAL NOTES AND BIBLIOGRAPHY 257 



ported by Millot {92, 93, 94}. Schaeffer's article {97} 

 gives a good synopsis of ancient forms. 



The pineal eye in extinct and recent vertebrates is dis- 

 cussed by Young {73, pp. 102, 162}, Gregory {33, pp. 

 338, 526} and Bridge {49}. An older but definitive work 

 on the subject is Gladstone and Wakeley's monograph 

 {88}. 



In the higher animals the pituitary gland is a complex 

 structure separable into two major divisions. The pre- 

 ferred name for the gland as a whole is 'hypophysis* 

 {hypo = under; physis = nature) , based on the fact that 

 it is located 'under' the brain. One division, the adeno- 

 hypophysis (aden = gland; + hypophysis) contains tis- 

 sues known as the pars distalis (= anterior pituitary), 

 the pars tuberalis, and the pars intermedia, all of which 

 have an obvious glandular structiire. The second divi- 

 sion, or neurohypophysis {neuron = nerve; + hypophy- 

 sis) or neural lobe, is so named because it is composed in 

 great part of nerve fibers, with minor obviously glandu- 

 lar elements {62}. 



The adenohypophysis secretes several hormones which 

 promote metabohc processes in the tissues generally and 

 in other glands, and which are therefore 'tropic' {trope 

 = adjectival form meaning 'to turn') hormones, of which 

 the growth hormone, the adrenocorticotropic hormone 

 (ACTH), and the thyrotropic hormone are generally fa- 

 miliar. That the adenohypophysis was functionally ac- 

 tive in the ostracoderms is indicated by the fact that 

 extracts of the mammalian gland induce changes in sec- 

 ondary sex characters in the cyclostomes, as well as ovu- 

 lation in the fishes and Amphibia. 



The neurohypophysis secretes the antidiuretic hor- 

 mone (ADH), the oxytocic hormone (which causes con- 

 traction of the pregnant uterus), and the amphibian 

 water-balance' hormone, while the pars intermedia se- 

 cretes the melanophore-expanding hormone. 



