BRAINS AND SPINAL CORDS IN ATAXIC PIGEONS 



123 



The spinal cord is shortened in the affected subjects. None of 

 the cases presents either a scoliosis or kyphosis of the vertebrae. 

 The medulla oblongata is reduced in size in both the ventrodor- 

 sal and transverse diameters. Nowhere in the brain or spinal 

 cord can there be observed a defect of any region with the naked 

 eye or with a lens. The cerebellum viewed from a cut surface 

 in sagittal section, after fixation, exhibits a rather round outline 

 in the affected specimen, while in the normal the anterior, dorsal. 

 and posterior margins are easily distinguishable, the whole ap- 



TABLE 2 

 Length of spinal cord 



*£ 



« £ 



Length of the whole spinal cord in 

 millimeters 



Length from the upper part of the 

 cervical cord to the beginning of the 

 upper intumescent a 



Length from the upper part of the 

 cervical cord to the beginning of the 

 lower intumescentia 



S3 



161 



57.8 



118 



pearing as a five-angled polygon. All the lobuli and sulci of the 

 cerebellum are sharp and well defined in the normal specimens, 

 while in the affected specimens the lobuli are thin and flat and 

 the sulci shallow, the whole appearing much more indistinct. 

 In each, however, the total number of lobuli is the same. 



The consistency of the brain substance is the same in both the 

 affected and normal birds; one can feel no sclerotic hardness in 

 the affected brains. 



The visceral organs in all affected birds reveal no abnormal 

 conditions except that the testes in pigeon no. K172 are somewhat 

 rudimentary (one-third of normal size). 



