(1951/1952) for fetuses of various crown-rump measurements. The epidermis was abraded with 1% acetic acid and the dry specimen was produced by treatment with turpentine. In this study, morphological differentiation of the dermo-epidermal junction was clearly seen. Specimens used for this technique must be fresh, and those fixed in formalin or alcohol are no use. In these specimens, an inspection of the whole surface, which is essential for the dermatoglyphic examination, may be disturbed by contraction and wrinkling of the epidermal tissue during treatment.On the other hand, Chacko and Vaidya (1968) observed the surface of the dermis using macerated volar skins from human newborns and adults and 243

The electrical resistivity of black phosphorus has been measured under high pressure. Two anomalies are observed at 42 and 108 kbar, associated with the transition from the orthorhombic to the rhombohedral phase and from the rhombohedral to the simple cubic phase, respectively. The former occurs in the vicinity of the vanishing of the energy gap of the orthorhombic phase. The simple cubic phase has a clear positive temperature coefficient of resistivity, but the absolute value of the resistivity is higher than those of usual metals. A preliminary experiment under very high pressure using “sintered-diamond” anvils has shown a sign of a phase transition from the simple cubic phase to a new phase at 0.8–1 Mbar.

The epidermal ridges of the rat (Rattus norvegicus), which are distributed only on the volar pads and digital apices, were studied. Examination of the ridges was difficult on the epidermal surface, as the undulations expressed on the epidermis are weak. Therefore, the dermal surface, prepared by alkaline solution treatment, was inspected by scanning electron microscopy and staining with toluidine blue. The dermis of the pads and digital apices is composed of ridged and rippled areas. The ridged area, where sweat ducts are distributed, is constructed of grooves and ramparts. Frequently, the sweat duct is surrounded by a dermal collar, and the groove is separated by a dermal partition. The grooves and ramparts display dermatoglyphic configurations, such as whorls, loops, cusps, triradii, and some other patterns, which are peculiar to each pad and digital apex and comparable to dermatoglyphic patterns of man and other primates.

The frequency of minutia types was studied in finger prints of 77 males and 82 females. Dermal ridges were clearly printed by a revised method for this purpose.The fork index, which represents the frequency of forks in minutiae, is higher in females for each finger than in males. It differs on each finger, i.e., low on the digit I, high on the digits, 111, IV and V, and intermediate on the digit 11. The mean of the index for each finger distributes from about 15 to 24. Bilateral difference is not evident. The correlation coefficient between right and left hands ranges from 0.52 to 0.79. Forks appear more frequently in ulnar loops than in whorls. It is revealed that the occurrence of forks differs in dermal regions.

Development of the dermal ridges in volar skin was investigated in 28 pigtailed macaque (Macaca nemestrina) fetuses of known gestational age, ranging from 51 days postconception to newborn. Histology, scanning electron microscopy, and staining of the abraded dermal surface were used in the study. Morphological features of the dermal-epidermal system and their changes with advancing age are described. Chronology was established for stages in the development of the volar skin, i.e., the differentiation of the primary and secondary epidermal ridges (PER and SER) at the undersurface of the epidermis corresponding to the formation of primary and secondary dermal ridges (PDR and SDR) and the development of the dermal papillae. PDRs were first seen at 55 gestational days and SDRs at 93 days. Differentiation of sweat ducts occurred over the period between 60 and 119 gestational days. A regional sequence of differentiation starting with the digital apices of the hand and ending in the calcar area and the phalanges of the foot was documented. Generally, morphogenesis in the macaque was accelerated relative to that in the human fetus by approximately 3 weeks.