BRAINS AND SPINAL CORDS IN ATAXIC PIGEONS 119 



support of the trunk, is short and the feathers are worn down, and 

 appear as if they had been cut off with a scissors (fig. 2). 



Pigeon no. K172. Keeps quiet and still as if sleeping, swaying 

 only the head and neck toward the side and a little backward. The 

 bird assumes the same position as the two previous ones. A wink of 

 eyes is often observed. No spontaneous nystagmus in head or in 

 eyes can be seen. The bird reacts to sounds. The most lateral of the 

 three front toes of the right foot is bent backward rather than forward. 

 The tail is shortened and has only rough feathers. This bird cannot 

 fly at all. When excited the bird rises up and a little to the side and 

 then bends backward slowly in clonic contraction till the forehead 

 touches the back; with flapping wings a somersault is made backward 

 or the bird falls to the side. From December 18th, the pigeon could 

 not maintain the body in a standing position, but fell every five seconds 

 to the side and backward. When it fell on the back it could hardly 

 restore its normal position. On January 14, 1918, the bird was killed 

 (fig.3). 



Pigeon no. K158. Is the most slightly affected one. Owing to the 

 tipping or swaying of the head and neck toward the side or forward, 

 the rapid cooordinated movements of feet and legs forward or to side 

 can be observed. Sometimes to maintain equilibrium in these irregular 

 movements the bird flaps the wings. These movements occur about 

 twelve times a minute, but the movements are slight and the restora- 

 tion of the body position occurs quickly. During the whole period of 

 observation, it never tipped or swayed backward. Bird walks swaying 

 from side to side just as is done on board ship in a rough sea. It will 

 not fly alone, but if set free in the air, it will fly to a higher level than 

 the position where it is set free. At rest the body is supported on for- 

 ward stretching legs with tail on the floor. Only a slight deformity 

 of the toes on both sides is seen. Killed February 18, 1918. 



As for the three healthy birds, they never revealed any abnor- 

 mality of movement during more than three months of observa- 

 tion, but lived a lively life, cooing, flying, or else perching on the 

 limb of the small tree in the cage. 



METHODS OF PREPARATION 



In reference to the examination of the central nervous system 

 of the birds, we must remember that the anatomy of the normal 

 tracts and nuclei of the pigeon is yet much in the dark, notwith- 

 standing the works of Stieda ('69), Turner ('91), Brandis ('93- 

 '96), Friedlaender ('98), Wallenberg C98-'06), Edinger ('03- 

 '08), Ramon y Cajal ('08), Frenkel ('09), Kiihn and Trendelen- 

 berg ('11), Shimazono ('12), Ingvar ('18), and others (Kreis, 



