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Dynamic responses of stomatal conductance to lightflecks (15 s to 5 min) were observed in the tropical understory plant Alocasia macrorrhiza. Brief observations were also made on step changes in light, flashing light and short low-light periods (darkflecks) after stomata had reached steady state conductances in high light. Stomata opened substantially even in response to very short lightflecks, with maximal opening being reached about 20 min after the end of the lightfleck. These responses are compared to those of a semi-mechanistic stomatal model consisting of three steps in series: a biochemical signal which responds directly to light, producing osmotic changes within the guard cells which, in turn, drive the movement of water into the guard cells. The rate of change of each component was assumed to be given by the difference between the current state of that component and the state of the previous component in the series divided by a characteristic time constant for each step. This model allowed excellent description of observed responses to lightflecks, including the fleck-length dependence of stomatal opening, the lag between the end of the lightfleck and the time of maximal stomatal conductance and the response to multiple flecks. However, agreement with predicted responses to flashing light and darkflecks was poor. Good agreement could be restored by using different time constants for the initial biochemical step, suggesting that the speed of the initial biochemical response is not constant but dependent on the current physiological state of the stomata. For leaves experiencing predominantly low light, punctuated by relatively short and infrequent periods of high light, this model allows good description of the dynamic changes in stomatal conductance.

The fatty acids of the total lipid extracts made from 10 tropical storage organs (Alocasia macrorrhiza, Colocasia esculenta, Dioscorea alata, D. bulbifera, D. cayensis, D. rotundata, Ipomea batatas, etc.) were studied. The high occurrence of the C18 unsaturated fatty acids (linoleate and linolenate which together contributed over 50 % on average of the total fatty acids), conferred a high level of unsaturation on almost species. Compared with similar storage organs of temperate regions, there was a definite reduction in the degree of unsaturation. This was brought about by a general increase in the intrinsic values of palmitate and oleate.

The identity, composition and concentration of each of the major lipids found in Alocasia tubers were investigated using a combination of chromatographic procedures. On a weight to weight basis, the neutral lipids, glycolipids and phospholipids comprised 60.5, 19.0 and 20.5% respectively while the total extractable lipids accounted for 0.6% of the dry weight. In addition to the conventional lipid classes of tubers, the presence of tri- and tetragalactosyl diglycerides was confirmed. The predominant fatty acid in each lipid class was linoleic acid with palmitic, oleic and linolenic acids being the other ones. In general, a high degree of unsaturation (66%), similar for most tuber lipids, was established for the component fatty acids of Alocasia.

Pottery making is still practised among the Yami tribe, Botel Tobago, although the artifact has been abandoned at one time or another by the other tribes of the Formosan mainland. According to the economical calender of the Yami, it is done in the month of 'Paruptogun', or September, and restricted to the men who manufacture such earthen ware as the Puraranum (water-jar), Wanga (boilingpot), Waga (earthen bowl), etc.The plastic clay, which is decomposed andesite or agglomerate that prevalent n the island, is obtained from certain points along the valley, and upon being brought to the village, is first passed between the fingers in order to eliminate the small rock's fragments and grits, and kneaded well without adding any sand. As soon as the Yami has finished gathering the clay, the fuel which had been left in the mountains to dry is transported to the sand beach, where it is again dried in the sun.The Yami mould the clay into a well-shaped pot with great ingenuity without employing the potter's wheel. A lump of the prepared clay is shaped with the hands into the form of a cylinder, the round base of which is laid on a leaf of the Raon grass (Alocasia macrorrhiza SCHOTT) and placed upon a board. The worker next pats the pot from the outside with the Paparo (patting club) in one hand, and supporting that part of the spot which is being patted from the inside with a flat stone in the other hand, thus building up the rough shape by gradually thinning and expanding the clay. The roughly made pot is moreover beaten out into shape with the Pipikpik (patting battledore) in one hand and a flat stone in the other. When the pot has acquired the desired shape, the outside is scraped with the Tatari or bamboo stick. The pot is left to dry in the wind, but out of the sun for about three days. The firing place is a cleaned space of ground on the sea-shore, a fine day with little or no wind being chosen. The fuel, which is cut up into lengths of a meter or so, is piled up in the form of a square block on the ground, and the pots are placed on it with their bottoms resting on the fuel laid side by side. More fuel is then added above and around the sides of the pots, and then being fired on the top of the fuel. Pots are baked two or three hours after the fuel is fired. The moulding of the clay and the firing of the pottery require great skill, with the result that the pot is often broken. Consequently, many taboos are observed among the potters in the pottery making season.Explanation of Textfigures.1. Diagrammatic sketch showing the manner of holding the flat, circular stone from the inside of the pot.2. Pipikpik or patting battledore (Left) and Paparo or patting club. (Right).3. Ipamarun-so-waga with section.4. Pasasakuvan-so-waga or mould used for making the Waga or earthen bowl.5. Moulding the clay into a cylinder.6. Adjusting the shape of the pot with the Pipikpik or patting battledore.7. Placing the pots in a depression in the piled fuel preparatory to firing.

The thiamin, riboflavin, and nicotinic acid contents of sweet potato (Ipomea batatas, taro (Colocasia esculenta), giant taro (Alocasia macrorrhiza), giant swamp taro (Cyrtosperma chamissonis), taro (Xan-thosoma spp), yam (Dioscorea alata and D. esculenta) were determined for fresh and 40°C dried material obtained from six South Pacific countries. Losses on drying at 40°C for 2-3 days were 10-15% for the three vitamins. Sweet potato contained the largest amount of thiamin (40-120 μg/100g fresh weight) and along with Colocasia esculenta and Xanthosoma spp. the largest amounts of nicotinic acid. The root crops provided inadequate amounts of thiamin, riboflavin, and nicotinic acid with values ranging from 12-123, 12-59 and 220-1310 Hg/100g fresh weight, respectively. Losses on cooking were about the same for all vitamins and root crops, with about a 20% loss on boiling (water retained) or baking and about a 40% loss on boiling (water discarded).