FLEXORS AND EXTENSORS. V 



In places these are attached by tendons to levers, connected on the 

 fore leg to the elbow, trapezium, extei'nal sessamoid and pedal bones, 

 and in the hind leg to the patella, calcis- — point of the hock — ses- 

 samoid and pedal bones. 



These attachments have a great deal to do with locomotion. Anato- 

 mists group the lower muscles as flexors and extensors — the office of 

 the former being to flex the limbs by pulling them up, the latter to 

 extend them and thrust the foot forward ; and the tendons which 

 convey the force to the extx'emities are also called flexors and exten- 

 sors. It seems to me that these terms have caused a misapplication 

 of the uses of these motors by those who have only a limited knowl- 

 edge of the functions of the muscles, and have associated the most 

 }X)wei-ful with the duty of merely flexing the limb. This is an erro- 

 neous conclusion, for the flexors of the fore legs give the last and 

 immense propulsive efi"ort to hurl the body through the air in the 

 fast gallop ; and though the fast trot depends more on those of the 

 posterior limbs, all are called into the service of progression. The 

 flexors are elongated when the foot is thrust forward by the contrac- 

 tion of the extensors, and the di-awing up of the tibres throws the 

 body along. 



To properly understand the eflect of toe-weights on the trotter, it 

 will be necessary to give attention to the action of the race-horse, 

 and proving the truth of that which seems at first paradoxical, that 

 weight is a drawback to one, an advantage to the'other. And now, 

 without the aid of the instantaneous photograph I should be 

 completely at fault, without cue or scent to guide me on the trail. 

 To be fully understood by readers, it will be necessary to get the 

 cartoons published by Muybridge, for words are inadequate to give 

 a proper understanding of the subject. The illustrations of the fast 

 gallop are on one card, there being eleven pictures of Sally Gardner, 

 the eleven covering one stride. I^he cameras which caught and 

 recorded the shadow of the flying animal were placed twenty -seven 

 inches apart, the slides being opened and closed by an electrical 

 apparatus, so that there was only an exposure of less than the two- 

 thousandth part of a second, the whole stride of 265 inches being 



