•2f) 



|)usw('sscil ;it this passiigc for a sliorl dislaiice Iwu kiyci.s, willi tlie 

 otlu'i' Katanliiiii and willi man tlie M. Irausv. suddenly, with an 

 acnto line, niodities its fonrse behind (he M. reetiis into a eonrse 

 in front of the hxtter. 



The condition of liie M. transversns, as it shows itself willi Kata- 

 rrliini and with man, is eeitainly not a primary one. Tiie anatomy 

 (if the slieatli of the M. rectus of Amiiiiii)ia and Reptilia teaches us 

 thai tiiere llie M. transv. rnns entirely behind the M. rectus, and 

 tiie ontogeny of the abdominal niusoidature of Urodeles" shows us 

 that this condition is the primary one. As now moreover with all 

 I'latyrrhini the .M. ti-ansv. [lasses iiehind the M. rectus, there can no 

 longer exist any doubt; decidedly the relation which with Katarrhini 

 and with man the M. transversns bears to the M. rectus is a second- 

 ary one. With ancestral forms of monkeys of tiie old world and 

 of man the M. transversus ran behind the M. rectus, as it does 

 still with IMatyrrliini. In the phylogenetical development of these 

 groups of Primates an inlluencc has been at work^ in consequence 

 of which the M. rectus |pieicos in the caudal part the M. transv., 

 so that the latter nuiscle in the caudal |)art is found on the anterior 

 sni'face of the M. rectus. 



With most J<atarrhini the M. Iransv. luodilies its relation to the 

 .M. reclus siuldcnly, in an acute line; with Maeacus rhesus the 

 aponeurosis of the .M. transv. possessed at the modification of its 

 direction for a short distance two layers, i.e. the M. rectus does 

 not ]>iercc the .M. transversns here ahruptly, at I'ight angles, but 

 gradually, so that the ÏM. rectus is situated for a short distance in 

 the mass of (he ^I. Irans\ersns. 



The relation of the .1/. oh/iq/ius iiili', iiiis to the M. rectus shows 

 with (he diirercnl monkeys also great dillerences. With Katarrhini 

 the M. obli(|. inl. runs entirely before the M. I'cclus; with Ateles 

 paniscns on tlic contrary entirely behind that muscle. With all 

 I'latyrrhini, with the exception of .Ateles paniscns, with man and 

 also with a ( 'ercopilhecus cynosurus I examined, we lind conditions 

 in which the lelation of the inlernus aponeurosis to the ^I. rectus 

 is ((uili' dillereut in the cranial part IVcun that in the camlal one. With 

 tli(> majority <ü' Platyrrhini we find that the internus apeuniu'osis 

 runs in the cranial part iiehiiul the M. rectus, and in the cauilal 

 part before the AI. rectus; conseipienlly the M. reclus pierces the 

 M. obliii. int. ;, usually the piercing takes [ilace gradually at an 

 acute angle, so that the internus aponeurosis jiossesses for a short 

 distance two layers. With Ateles hypoxaiithus the aponeurosis vuw^ 

 in the cranial [larl Iiehind the AI. rectus and includes in the caudal 



