SUMMARY OF STRUCTURES 707 



COEFFICIUMS in- THE NlCLllS OF GoLL IN 1111 lllGHFK AnTHKOI'OIDS 



SpCC'lfJ 



Gorilla 



Chimpanzee 

 Orang-outang 



CoiisidcTed in rc-Iation witli tlu' nilcrnu'diatc pninati's, tlu' nuclc-us of 

 Cioll in the great anthropoids chscloscs a rather unexpeeted eqiiahty. It 

 nii.uht be presumed that with the dellorescenee and final disappearance of the 

 tail, Xhv nuclear structures in Coil's column would so materiallx fall oil that 

 there would he a distinct mieriority ol it in the hifj;lu'r iorms. This, however, 

 does not prove to be the case. The deliciency which the great anthropoids 

 would naturallx be expected to show because ot the absence of the tail is 

 surprismgl\ wanting. Therefore, some factors tending to maintain the general 

 ec[uality ot this nuclear structure among the intermediate primates and the 

 higher anthropoids must exert a decisive influence. \\ hile it is impossible to 

 prove conclusively at present what the exact nature of this factor is, it 

 ajjpears none the less to be embraced in those spt'cializations ot the hindlimb 

 for locomotion upon the ground as \\v\\ as lor the assumption of the erect 

 posture. That there is some such modil\ ing iiilliiciice at work is indicated by 

 a comj^arison ot the gibbon with the" greater anthropoids. In this H\lobatc 

 form the luicleus of Coll reaches low-water mark, being less in its dimensions 

 than in any of the other ]:)rimates. The explanation appears to be in tin- fact 

 that the animal possesses no tail, and has specialized the hindlimbs but little, 

 either tor [purposes ot locomotion upon the ground or for its arboreal 

 locomotion. 



Compared with thi' lowfr primatt's, the great anthropoids show some- 

 thing approaching an cc|ualit\ in the size of the nucleus ol Coll, although the 

 lower forms bring forward one striking instance to illustrate the neural 



