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USE OF THE SUTURES. 



Why the fj- 

 tares are obli- 

 terated, &c. 



of the ufe of futures comprehends and accounts for thofe 

 concomitant circumflances, wliich were confulered by older 

 anatomifts as their real ufe ; and, as far as I can fee, h not con» 

 tradicled by any fad connecl^'d willj them. 

 Other remarks I^ 't be afkcd, for infiance, why at the futures there is a 

 aad inferences. Wronger adliefi on of the dura mater internally and periojieum 

 externally than in other parts of the (kull ? the anfwer is, that 

 Ihefe membranes with their vefTels are coi>tinued into the 

 futures, to form conjointly the fecretory organ, by which the 

 bones are extended. 



If it be afked, why ^there is a greater vafcularify or an 

 appearance of blood-velTels pafling through the futures? it is 

 perfed^ly conliflent with this opinion to anfwer, that the increafe 

 of blood goes to this fecretory organ, for the purpofe of the 

 cxtenfion of- the bones. 



The explanation here offered accounts alfo for the general 

 obliteration of the futures after a certain period of life ; for 

 the bones having then arrived at their full tize, the organ for 

 the fecretion of ofleous matter is no longer needed ; it fnrinks 

 and is abforbed, and the bones gradually coalefcs ; by which 

 a further advantage is derived, that of an acceffion of ftrengih 

 to the cranium at large. 



lis locis conglutinantur, verum tamen non nifi in embrionibus 

 ad fonticuJos, ut aiunt, haec linea notabili latitudiiie, obiervatur. 

 Oflibus enim capitis hie locorum ceiebro crefcente, placide quafi 

 deduftus, cartilage augetur, latior evafura, nifi prittina pars fimul 

 in OS mutaretur, inde offa calvarix, eodem modo, quo ofia longa 

 deduftisepiphyfibus, vel quod unum idemque eft, marginibus cref- 

 cere, liquet, etfi in ofTibus, longis futura epiphyfes inter et diapky- 

 lin non crif'petur. 



" Quo junior igitur infans, eo minus crifpa et implexa futura, 

 vel ut reftius loquar, linea cartilaginofa augufta, ofla jungeus, 

 obfervatur. Quum vero aufta aetate ofla, crei'ente cerebro, dedu- 

 cuntur, eorumque, craflitudo adpofita cum interna3, turn externa: 

 potiffimum tabulje, (intern?e enim increnientum citius abfolutum 

 videtur) mafia olTea, augctur, non poteft non efle, quin haec crifpa 

 futurae forma, quum quidem nafci coepit, externa in fuperiicie tam- 

 diu, augeatur, donee tandem ipfa ea quam maxime impediat, quo 

 minus cerebrum calvariam ulterius deducere poffit, quod pubertatis 

 tempore accidit. Rarilfime haec olTificatio ad aetatem viriiein ufque 

 detiuetur.'" — Soemmerring de corporis Humani Fabrics, page 212. 



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