Hydrocephalus 737 



matter, leads ordinarily to the death of the fetus as soon as the 

 umbilic circulation is suspended. 



The effect upon the skull is interesting, and has an important 

 relation to the question of delivery. The bony skull is usually 

 incomplete, and the principal portion of the tumor or enlargement 

 is wholly devoid of any osseous covering, and consists merely of 

 the skin and vestiges of the meninges of the brain. At the base 

 of the tumor, the bones of the skull spread outward and then 

 upward to constitute a chalice- like cavity with irregular borders. 



The cause of hodrocephalus in the fetus is unknown. It is 

 observed in all animals, but is most frequently seen in the calf 

 and somewhat rarely in the foal. 



The diagnosis is comparatively easy when the fetus presents 

 anteriorly, but may become somewhat difficult in the posterior 

 presentation. When the fetus presents anteriorly, the obstetrist 

 usually finds upon inserting his hand that the cranium is abnor- 



FiG. 123. Hydrocephalus. Calf. Skull from Fig. 122. (Harms). 

 mally enlarged and soft or fluctuating. Somewhat rarely the 

 hydrocephalic cranium is complete, the osseous walls completely 

 enclosing the abnormal brain. At first there may be difficulty 

 in identifying the head, because of the great disproportion and 

 its soft, fluctuating character. The actual diagnosis can be made 

 only by identifying some definite parts of the head, .such as the 

 mouth, nostrils, ears or eyes, and determining that the enlarge- 

 ment has a definite relation to these. 

 47 



