HYPOPHYSIS CEREBRI 307 



the average weight was 66.7 eg., in fifty women, 73.1 eg. 

 His figures are high owing to the fact that his subjects 

 were mentally alienated; it is said that, in this class of case, 

 the weight of the hypophysis is in inverse ratio to that of 

 the brain. According to Erdheim and Stumme, the average 

 weight of the hypophysis in the male is, in the second decade of 

 life, 56.3 eg. ; in the third decade, 59.3 eg. ; in the fourth decade, 

 64.3 eg. From then onwards the weight gradually declines ; in 

 the fifth decade it is, on an average, 61.4 eg. ; in the sixth, 60 eg. ; 

 and in the seventh, just a shade higher, 61.2 eg. The average 

 weight of the hypophysis in women who have never borne a 

 child is, decade for decade, almost identical with that of men ; in 

 women in whose pregnancy anamnesis is unknown, the average 

 weight is generally higher 71.6 eg. as against 60. i in nullipara 

 and 61 in men. During pregnancy the hypophysis undergoes 

 a remarkable increase in weight. The minimum weight of 65 eg. 

 in a primapara is larger than the minimum weight in a nullipara; 

 even the maximum known weight of 75 eg. in a nullipara does 

 not equal the average figure of 84.7 eg. in the primipara. The 

 increase in the size of the hypophysis takes place almost ex- 

 clusively in the length and breadth ; in the anterio-posterior 

 diameter it is barely noticeable. At the termination of pregnancy 

 the weight is again reduced, but should pregnancy again occur 

 it rises to a figure even higher than before. The average weight 

 of the hypophysis in the multipara at the termination of normal 

 pregnancy is 106 eg., a figure considerably in advance of the 

 weights which have been ascertained in the case of the primipara. 

 The difference in the maximal weights is even greater, that of the 

 multipara being 165 eg. and that of the primipara no eg. The 

 increase in weight is accompanied by structural changes which 

 will be described later. 



The hypophysis is supplied with blood by means of minute 

 branches from the internal carotid artery; the blood is carried 

 away into the circular sinus by small veins. 



Section of the hypophysis shows, even to the naked eye, that 

 the organ consists of two parts ; the anterior portion is a hard, 

 kidney-shaped lobe, concave posteriorly, pale yellow to grey-red 

 in colour, and represents the epithelial or glandular portion of 

 the hypophysis (the true pituitary gland). The posterior portion 

 is a smaller, rounded, white, soft lobe, situated in the concavity 

 of the anterior lobe; it represents the nervous or infundibular 

 portion of the organ (the true hypophysis or neurohypophysis). 

 The two lobes are joined together and enclosed in a common 

 fibrous capsule. The hypophysis is attached to the brain, as 

 previously mentioned, by means of the funnel-shaped infundi- 

 bulum. The latter is a prolongation of the floor of the third 

 ventricle, the tuber cinereum ; it first forms a hollow sphere which 

 represents a prolongation of the third ventricle, it then penetrates 



