THE GAITS IN PARTICULAR. 



535 



It is also with absolute accuracy that M. Chenier advances that 

 these hoses alternate very regularly with the fundamental bases already 

 known. 



M m 



m \M ^ m- 



X 



Fig. 227.— The walk: anterior right tripedal 



contact. 



(From the instantaneou.s photographs 



of Lissa.) 



Fig. 228. — The walk: right diagonal contact. 



(From the instantaneous photographs 



of Lissa.) 



Fig. 229 is the exact notation of the walk with equidistant beats, 

 which has been photographed by M. Anschiitz. 



Fig. 229.— Notation of tlie ordinary walk. 

 (From the instantaneous photographs of Lissa.) 



1, 3, 5. 7, tripedal bases ; 2, 6, lateral bases ; 4, 8, diagonal bases. 

 The duration of the fundamental bases is twice that of the supplementary, which equals one- 

 seventh of the total contact of each foot. 



Evidently the periods of contact upon three members are so much 

 shorter and less appreciable as the rhythm of the gait is more precipi- 

 tated. They occur at the time of each change of contact, and, as there 

 are four of these changes, two for each biped, anterior and posterior, 

 there should also be four supplementary tripedal bases.^ 



If M. Marey's instruments, delicate as they are, have not registered 

 them, it is because they occur at the instant of the raising and resting 



1 Like markings on the extremities, the tripedal bases are designated by the name of the 

 isolated member (anterior or posterior) which contributes to form them. Example, the base PG. 

 PD—AQ, will be called tripedal anterior left. 



