SPLEEN 45 



Pituitary Body. When this body is completely removed 

 from dogs death results in from one to two days. Although 

 the animal may make good recovery from the immediate 

 effects of the operation, it soon becomes comatose, with long- 

 drawn inspirations, feeble pulse, limp muscles, subnormal 

 temperature, and with characteristically curved spine. Death 

 ensues quietly. Partial removal of anterior or posterior lobes 

 gives rise to no disorder, but complete removal of the anterior 

 lobe alone gives the same results as total extirpation of the 

 gland. 



The pituitary is said to hypertrophy after thyroidectomy, 

 and the colloid formed by the pars intermedia is said to be 

 increased and to invade the pars nervosa of the gland. This 

 colloid, however, seems to contain no iodine. In man, patho- 

 logical changes of the pituitary are not associated with myx- 

 edema, but with acromegaly, a condition in which the bones 

 of the limbs and face, especially of the lower jaw, become 

 enlarged. Whether this is due to a hypo- or a hypersecretion 

 is not known. 



All three parts of the pituitary contain a substance which 

 when injected into an animal produces a depressor effect. But 

 since this is an effect of so many extracts of tissues, especially 

 nervous tissues, it is not regarded as specific to the pituitary. 

 The posterior lobe including the pars intermedia contain, 

 in addition, an active substance producing a pressor effect. 

 This is produced not only by a constriction of the arterioles, 

 but by an increase of heart beat. The rise of pressure lasts 

 a long while, and a second dose injected before the effects of 

 the first have passed off is without further effect, thus dis- 

 tinguishing the pituitary from the suprarenal. 



Spleen. The function of this organ is very little under- 

 stood. It may be removed from the organism without serious 

 injury,' giving rise, it is asserted, to an enlargement of lymph 

 glands and to an increase in the amount of bone marrow. 

 It has also been found that the number of red blood corpuscles 

 is diminished. The following suggestions of the function of 

 the spleen have been offered: 



1. That the spleen manufactures blood corpuscles. This 

 is without doubt true in man during fetal life and at birth, 

 but it is not known that it continues throughout life. 



