HURZELER (1948) reported an individual of red howler monkey on which second upper molar the direct connection between the protocone and hypocone is not seen; the Nannopithex-f old (this structure must be regarded as the postprotocrista as discussed in the text) runs from the protocone postero-buccally and extends between the hypocone and metacone. 70 individuals of howlers were examined; all of them show the direct connection between the protocone and hypocone, and thus it is concluded that the specimen shown by HURZELER is an example of specifically rare case. Because the Miocene Stirtonia which gave rise to extant howlers (Alouatta) shows no direct connection between two cusps mentioned above, the connection between the protocone and hypocone seen in almost all howlers is safely regarded as a derived or secondary character.
Based on the hypothesis that the Eocene Omomyidae and its allies might be an ancestral stock to whole South American monkeys, and compared them with omomyids, the following "primitive"characters of molar structure among platyrrhines are discriminated;
1. The hypocone is present.
2. The entoflexus is deep and long transversely.
3. The postprotocrista extends to the base of the metacone.
4. Each cusp is distinct and rather tall.
5. Upper molars are wider than long.
6. The third molar is present.
Among extant platyrrhines, only squirrel monkeys (Saimiri) have these six primitive characters. Cebus, which is usually treated as an unspecialized monkey among platyrrhines and thought to be closely related with Saimiri, attaines several derived characters. Here, it is concluded that Saimiri retains primitive characters which were attained by the ancestral stock of platyrrhines. Based on these points of view, a provisional phyletic tree is introduced.

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A rapid straightening up movement from a moderate forward-bending position was performed by five male adults under three conditions: without any external load; with an additional load suspended by the hands; and lifting a load on a platform in front of the subject as quickly as possible. Straightening up under the three load conditions began in response to an auditory signal or spontaneously, without an auditory signal. The surface electromyograms of the erectores spinae at the level of the 4th lumbar vertebra, the gluteus maximus, and the semitendinosus were led bipolarly. The output of an acceleration meter fixed to the 7th cervical vertebra was measured simultaneously to identify the period of the straightening up movement. The frequency of the appearance, and the duration of the silent period in the erectores spinae prior to straightening up were compared for the three external load conditions with and without an auditory signal.
The frequency of the appearance of the silent period prior to movement without an auditory signal did not differ obviously from the frequency with an auditory signal. An electrical silence when lifting a load occurred more frequently than when no loads were lifted or when an additional load carried by the hands. Thus a difference in the frequency of the appearance of the silence was found between lifting a load and not lifting external load. However, the muscle load of the erectores spinae in the preparatory phase before rapid movement while lifting a load was equivalent to the muscle load without an external load, because grasping a load with both hands and straightening up were carried out simultaneously. The silent period prior to movement over the maximum duration of the silence recorded in reaction trials was frequently recorded in spontaneous trials without an auditory signal. An intermittent electromyographic silence with a given interval was found preceding straightening up on the surface electromyograms of the erectores spinae, the gluteus maximus, and the semitendinosus and the beginning of the intermittent silence was before theauditory signal for the reaction trial.
The data suggest that the intensity of the muscular contraction of the erectores spinae seems to be related to the appearance of the silent period in the erectores spinae prior to rapid straightening up. It is assumed that the electrical silence would be inhibitory phenomenon related to the preparation of the brain for the development of a rapid voluntary movement. The fact that the silent period prior to movement which has been observed only on the surface electromyograms of the extremity muscles can be found also on the surface electromyogram of the erectores spinae of the trunk muscle is proved in this paper.

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In 1979, the author surveyed for the peoples of Sri Lanka; the Sinhalese (three groups by the areas), Kinnaras (occupational caste), and Veddas (two groups by the areas), and the somatological data on the adult 232 males and 180 females in total was collected, and in 1981, two kinds of the Tamils of Lanka were examinded in number of 66 males and 54 females. The detail and classification of those data obtained from the eight ethnic groups is shown in Table 1.

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This article concerns with secular changes of tooth to denture base discrepancy during Japanese prehistoric and historic ages, by means of morphological analysis of Japanese skeletal remains as well as living people.
Materials used were 122 skulls from the later Jomon, Kofun, Kamakura, Muromachi and Yedo eras. Two hundred and ninety living Japanese were also investigated. The frequency of discrepancy was surveyed by inspections of occlusion, and the amount of discrepancy in individuals was calculated from measurements of tooth size, dental arch length, and forward inclination of the mandibular incisors.
The results were as follows; 1, both frequency and amount of discrepancy have increased from the later Jomon to the modern ages, accompanied by several fluctuations. 2, increase of discrepancy seemed to be brought about by evolutionary changes of teeth and jaw bones independently of each other, and, 3. the major element which contributed to the increase was reduction of jaw bone size. Finally, the authors suggested that further studies on the relations of discrepancy to foods and eating behavior and also to dental diseases are required to analyse this problem in more detail.

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Although many data of cranial as well as other skeletal measurements have up to the present been accumulated in the field of anthropology, there can be seen few reports on their errors. In this article, the intra- and inter-observer errors of 22 measurement items, used frequently in Craniometry, were assessed and discussed.
Intra- and inter-observer measurement error variances of each item were firstly obtained through the analysis of variance for balanced hierarchal classification based on the data which were provided by six observers measuring the same five male skulls of Edo era independently twice. As a result, the greater intra-observer error variances were recognized, especially, in minimum frontal breadth, orbital breadth and facial profile angle (Tables 1 and 2). The significant systematic errors due to observers were found in eight of the 22 items, i, e., biauricular breadth, biasterionic breadth, orbital breadth and height, glabello-inion length, cranial base length, nasal height, and upper alveolar breadth (Tables 1 and 2).
Secondly, it was ascertained by the principal component analysis that there was no common error source among the 20 linear measurement items. Finally, the cluster analysis of the present sub-samples for assessing measurement errors and several samples from literature suggested that errors, especially inter-observer, might greatly affect the interpretation for the results of population studies (Fig, 1).
From the above, it was re-realized that any result based on measurements should carefully be interpreted taking their errors into account.

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The dentitions of three species of Colobus monkeys (Colobus polykomos, Colobus badius, and Colobus verus) are compared metrically for three characters: actual tooth size, rect angle (mesiodistal diameter×buccolingual diameter), and length-breadth index (buccolingual diameter/mesiodistal diameter×100). Comparisons of actual tooth size reveal that in general the smallest tooth size is found in C, verus, a greater tooth size in C, badius, and the largest tooth size in C, polykomos. On the contrary, the degree of sexual dimorphism decreases from C, verus to C, badius to C, polykomos. Accordingly it follows that the interspecific sex differences do not correspond to the interspecific differences in the general tooth size. Moreover comparisons of rect angle show more evident relations both in tooth crown area and in its sexual dimorphism. Inn the case of length-breadth index there are no further interspecific differences. These findings are discussed with comparative data in connection with body size dimorphism.

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From remarkable progress of human culture in the present days, acceleration of reduction of the human occlusion is predicted. It was attempted, therefore, to survey the generational differences of tooth to denture base discrepancy in current population as a basis for further estimation. Subjects of this study were 288 living people sampled from five generations (15-16, 25-26, 35-36, 45-46 and 55-56 years old, respectively), selected from populations of Koromogawa village. As the results, increase of total number of malocclusion was not obvious but decrease of maxillary protrusion and increase of anterior cross-bite was observed. These facts seemed to be an expression of alteration of facial morphology from prognathic to retrognathic pattern. The frequency of the discrepancy has increased from G-I to G-V, though there was irregular fluctuations. From the discussions on size of discrepancy, it seemed to be a fact that the progress of the discrepancy in the current age was induced by two ways, namely by enlargement of tooth size and by diminution of jaw bone.

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