348 



Not before 1852 did Gruber find (4) the sutura parietalis of Siniia 

 silenus and about 30 years after, Broca (10) found the second case, 

 from a species of monkey, the name of which is not mentioned. 

 After 1880 some new cases of the sutura parietalis of monkeys have 

 been found and in 1900 Frassetto (5) knew 24 examples which 

 in 1903 were augmented with about 50 by Hrdlicka (6). Hrdlicka 

 found his cases especially from Macacus, Cebus and Ateles. It is 



very remarkable that, in the other groups 

 of the Mammals, a sutura parietalis has 

 hardly ever been noticed. Even in 1903 

 not a single case was known so that 

 Schwalbe (7), wrote on page 405: 

 „. . . es ist nun höchst beachtungswert, 

 daß bisher in keiner anderen Säugetier- 

 klasse ein geteiltes Scheitelbein gefun- 

 den ist". And on page 410 he con- 

 tinues: „das Parietale bipartitum ist 

 eine im Primatenstamm aufti^etende neue 

 progressive Bildung, welche normaler- 

 weise aber zunächst nur seine Anfänge 

 im früher embryonalen Leben (Ende 

 des dritten Monats) erkennen läßt und 

 gewöhnlich durch frühe Yerschmelzung 

 zur Ausbildung eines einheitlichen Pa- 

 rietale führt, in seltenen Fällen dagegen 

 unter gewissen Bedingungen als doppel- 

 tes Scheitelbein persistiert; unter diesen 

 Bedingungen spielt congenitale Hydro- 

 cephalie eine hervorragende Rolle. Eine 

 atavistische Deutung des Parietale bi- 

 partitumist durch nichts gerechtfertigt". 

 And Hrdlicka (6) 1903 also says on page 232: ". . . no case however, 

 has thus far been signalled in any lower mammals than monkeys." 



And yet in 1901 Frassetto (8) seems to have found a case of 

 the sutura parietalis with the Carnivora, viz., with Ursus americanus. 

 Frassetto mentions this fact only very superficially and says: "Ursus 

 americanus: Divisione multipla in ambo i parietali (primo caso nella 

 letteratura)." Nothing more, not even a picture. This is the first 

 communication of the sutura parietalis of a group of Mammals which 



Mus decumanus var. albus. 

 Sutura parietalis. 



