Journal of the Anthropological Society of Nippon

Distribution of the Ge Groups among the Thais

Hachiro NAKAJIMA, Motoyuki URANO, Adirek JARUMILINTA

1965 Volume 73 Issue 3 Pages 69-71
Published: September 30, 1965
Released on J-STAGE: February 26, 2008

DOIhttps://doi.org/10.1537/ase1911.73.69

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The distribution of the Gc groups was investigated on 178 Thai adults, all of whom were in Central Chest Hospital, Bangkok, with tuberculosis. The phenotype frequencies were: Gc 1-1 66.85%, Gc 2-1 28.65% and Gc 2-2 4.49%. The goodness of fit was tested by the following equation: x²=n(c²-4bd)²/(2b+c)²(c+2d)² (d. f.=1) where, b, c and d meant the observed number of Gc 1-1, Gc 2-1 and Gc 2-2 respectively.
The results of test (x²=0.6917, 0.50>P>0.30) indicate that the distribution is in an agreement with HARDY-WEINBERG's law.
The gene frequencies calculated by maximum likelihood method were : Gc¹=0.8118±0.0207 and Gc²=0.1882±0.0207. The frequency of gene Gc¹ was higher than that of the Japanese (0.7730-0.7753; ISHIMOTO, 1963, OMOTO et al., 1964), Koreans (0.7586; OMOTO et al., 1964) or the Chinese (0.7693; CLEVE and BEARN 1961).

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Evolutionary Significance of Reduced and Supernumerary Teeth in the Dentition

Kazuro HANIHARA, Tetsuo MASUDA, Takeshi TANAKA

1965 Volume 73 Issue 3 Pages 72-81
Published: September 30, 1965
Released on J-STAGE: February 26, 2008

DOIhttps://doi.org/10.1537/ase1911.73.72

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Crown diameters in I¹ through M¹, except for I², were compared between den titions having conical or missing upper lateral incisors (Group C) and those having normal teeth (Group N), as well as between the latter and those having supernumerary mosiodentes (Group M). The purpose of this study is to find relationship of the tooth number anomaly to the normal characters as represented by crown diameters in the remaining teeth, and to give possible information in regard to the evolutionary significance of anomalies in tooth number, especially of the supernumerary teeth.
Employing statistical tests, it was clearly proved that the Group C had generally smaller teeth than the Group N, but the Group M showed almost no difference from the latter, though some exceptions were present for the upper second premolar in males. However this exception seems to be negligible if one realizes that this tooth is morphogenetically most unstable in the series of teeth examined here.
The fact that the teeth are significantly smaller in the Group C than in the Group N very likely shows parallel evolutionary trends of the reduction in the upper lateral incisors and the other teeth in the dentition.
On the contrary, insignificant difference in the tooth size between the Groups N and M seems to suggest that the supernumerary teeth, or at least the mesiodentes, have no evolutionary importance. This, in turn, might support the theory of accidental variation in tooth germs for the origin of the supernumerary teeth.

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Differential Fatiguability between the One- and Two-Joint Muscles

Masahiko SATO, Atsushi HAYAMI, Haruhiko SATO

1965 Volume 73 Issue 3 Pages 82-90
Published: September 30, 1965
Released on J-STAGE: February 26, 2008

DOIhttps://doi.org/10.1537/ase1911.73.82

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The present study was designed to confirm the differential f atiguability between the one and two-joint muscles by the frequency analysis of the EMG activities of each pair of elbow flexors (M. biceps brachii and M. brachioradialis), knee extensors (M. rectus femoris, M. vastus medialis, and M. vastus lateralis), and ankle extensors (M. gastrocnemius and M. soleus). The results are summarized as follows :
(1) The lowering in the frequency spectra was indicated to almost the same degree between the biceps brachii and the brachioradialis.
(2) Any remarkable difference could not be detected between the lowering in the frequency spectra of the rectus femoris and those of the synergisticarlly operating one-joint muscles.
(3) When the above results were obtained, it was confirmed that the total EMG activities of the two-joint muscles tested were never smaller than those of the synergistically operating one-joint muscles.
(4) The lowering in the spectra was much more marked in the gastrocnemius than in the soleus, whereas there was little difference in the contraction level between the gastrocnemius and the soleus.
(5) It was concluded that the deep one-joint muscle was difficult to fatigue as compared with the synergistically operating superficial two-joint muscle, and that there were little significant differences in the fatiguability of the superficial one and two-joint musles.

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A Morphological Study of Enamel-Dentin Border on the Japanese Dentition

Takuro SAKAI, Izumi SASAKI, Hajime HANAMURA

1965 Volume 73 Issue 3 Pages 91-109
Published: September 30, 1965
Released on J-STAGE: February 26, 2008

DOIhttps://doi.org/10.1537/ase1911.73.91

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The exterior surface of the enamel layer of the teeth has frequently beensubject of morphological, morphogenetic and anthropological considerations. But regarding the interior surface of the enamel cap (enamel-dentin border), a few studies have been reported. To ascertain the morphological relationships between enamel surface and enamel-dentin border of the maxillary median incisor, the enamel has been artificially removed by means of acids.

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