>3«2 FCETAL DYSTOKIA. 



the diameter of whose dropsical cranium was fourteen inches, and which 

 it was computed would contain about twelve litres of fluid (more than two 

 and a-half gallons). And Quesnel has also shown a skull of about the 

 same dimensions, to the Veterinary Society of Calvados et de la Manche. 



Mr. Olver ( Veterinarian, 1874, p. 481) describes the cranium of a hydro- 

 cephalic Foal which measured thirty-six inches in circumference, ten 

 inches from one orbit to the other, and twenty-seven inches from the 

 occipital crest to the nasal bones. At least twelve pints of fluid were 

 contained in the cavity, and the cerebral substance remaining was quite 

 disorganized, the durmater being much thickened. The cranial cavity 

 was almost wholly surrounded by bone ; the only portion which was solely 

 enclosed by skin was a space about four inches in circumference at the top. 



In the Museum of the Munich Veterinary School is a skull, the cranium 

 of which measures nine by eleven inches in diameter. 



Professor Lombardini {Giornale di Veterinaria, 1873) speaks of the head 

 of a Calf, the cranium of which was more than fourteen inches high ; it 

 was eight and a-half inches long, and four and a-half broad. This Calf, 

 with two others, well-formed, was aborted at six months, without any 

 injury to the Cow, which was six years old. There can be no doubt that 

 if the full period of pregnancy had been reached, this Calf would have 

 proved troublesome to extract. 



But these latter are quite exceptional instances, and are three or four 

 times larger than those usually met with. 



This accumulation of fluid takes place in the ventricles of the brain, 

 as has been ascertained from dissection by Rainard, Taiche, Chouard, 



Fig. 82. 

 Head ok a Foal affected with Hydrocephalus. 



Axe, and others, who have found the tumor formed externally by the 

 skin, and internally by the membranes of the brain, to which adhered a 

 thin layer of cerebral substance. The spinal cord, plexus choroides, and 

 cerebellum, have been generally observed to be intact, and ou\f the 

 cerebral hemispheres are destroyed more or less completely. 



Though this alteration, or rather destruction, of the brain is of so serious 

 a character, and though it must have begun at an early period of uterine 

 life, yet it does not appear to have much influence on the development of 

 the foetus, as this is usually found to be full grown, its skin covered with 

 hair and well-formed everywhere except in the head. Exceptional cases 



