300 
ready examined a small part of them. I have mdeed found a bipartite 
parietale in an embryo of about 19 days of Lepus cuniculus. The parie- 
tale was exactly like the one of the man represented by Ranks (1) 
on p. 54, fig. 32. But the incisions between the two centres are a 
little deeper and comparatively speaking everything was smaller of 
course. We must not rely on this one case, but it gives us a hint. After 
I have examined all the embryo’s I hope to revert to this subject more 
in detail. It appears that the sut. par. on human skulls occurs almost 
exclusively in the male sex. This preference does not exist with the 
monkeys. What can we say about this abnormality with respect to the 
other mammals? This too is still unknown. After I had finished this 
study my attention was drawn upon an article from Louk (23) which, 
to my regret, I have not yet been able to get and study. Probably 
the sut. par. is also mentioned there. I hope to revert to this after- 
wards. Finally I think it an agreeable duty to thank Prof. VosmMaER 
at Leiden and Prof. VAN DEN BROEK at Utrecht most cordially for their 
trouble to provide me with the necessary literature. I am much 
obliged to Messrs. Dr. JENTINK and Dr. VERMEULEN at Leiden and at 
Utrecht for the afforded material and for all kinds of information, 
as well as to Mr. Van Heurn for many skulls of Mammals and for 
his assistance. 
Rotterdam, Oct. 17th 1913. 
Papers cited. 
We especially refer to the lists of literature published by HRDLIORA, 
SCHWALBE, and FRASSETTO. 
1, RANKE, Die überzähligen Hautknochen des mensch]. Schädeldachs, Abh. d. 
k. bayr. Akad. d. Wiss. II Cl. XX Bd. II Abt. 1899. 
2. SCHWALBE, Uber geteilte Scheitelbeine. Zeitschr. f. Morphol. u. Anthropol. 
VI. 1903. 
3. HRDLIÖKA, Divisions of the parietal bone in Man and other Mammals. Bullet. 
Am. Mus. of Nat. Hist. vol. 19. 1903. Art. 8. 
4. KoLLMANnN, Lehrbuch der Entwickelungsgesch. des Menschen. Fischer, 
Jena, 1898. 
5. ToLDT (MAscHKA), Handbuch der gerichtlichen Medicin. Bd. III, p. 515. 1882. 
6. Grafv. SPEE, K. v. BARDELEBENS Handbuch der Anatomie d. M. I. Bd., II. Abt. 
Skelettlehre, ,,Kopf‘. 1896. Fischer, Jena. 
. SCHULZE, O., Grundriß der Entw.gesch. des Menschen u. d. Säugetiere. 
1897. Leipzig, Engelmann. 
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