BRAINS AND SPINAL CORDS IN ATAXIC PIGEONS 157 



due to the congenital atrophy of the cerebellum, mostly a malde- 

 velopment of the cortical layer, often with atrophy of the molecu- 

 lar, granular layers and also Purkinje cells. The reduction or 

 degeneration of the inferior and middle cerebellar peduncles is 

 usually cited (Menzel, '91). 



Many transitional types of these two diseases, however, have 

 been reported afterward in reference not only to symptomatology, 

 but also to pathological anatomy (Mingazzini, '05). Many 

 authors (Oppenheim, '00; Holmes, '07; Jendrassik, '11, and 

 others) at present believe these two diseases to be merely one 

 type of hereditary ataxia in which there may at times be a prom- 

 inence of spinal-cord involvement while at another time the cere- 

 bellar involvement predominates, according to the main locali- 

 zation of the affection. 



It is evident from the indicated pathological findings found in 

 the central nervous system, as. well as from symptoms exhibited 

 during life and from the detailed family history, that the disease of 

 our pigeons is familial and congenital and that it comes quite in 

 accordance with the so-called hereditary ataxia of man. 



The condition of static ataxia and the modes of gait from 

 'demarche ebrieuse' to somersault may be considered as a cere- 

 bellar disturbance or, if not, they must have at least a close rela- 

 tion to some important tracts, such as the direct cerebellar tracts, 

 which anatomically have a connection with the cerebellum. On 

 the other hand, the deformity in the toes found in three affected 

 birds seems rather to point to the so-called Friedreich's foot or 

 pes cavus which has never been recorded in a case of simple 

 atrophy of the cerebellum (Marie's disease), but is no doubt a 

 symptom arising from a lesion in the spinal cord. 



Thus our subjects are a type in which the spinal cord and the 

 cerebellum as well as the medulla oblongata are involved, pre- 

 senting on one hand Friedreich's ataxia and on the other hand 

 Marie's disease at the same time from both the symptomatical 

 and pathological points of view. Had we examined the spinal 

 cord only, it might have been a typical case of Friedreich's ataxia, 

 whereas the study of the cerebellum alone would have given us 

 that of Marie's disease. This combination of the symptoms and 



THE JOURNAL OF COMPARATIVE NEUROLOGY, VOL. 31, NO. 2 



