Newly ecdysed 4th instar larvae of some tetramolter strains having different genotypes on the sex-linked maturing genes, Lm^e and +^Lm, were subjected to high temperature of 38°C for 24hr, and effects of the treatment on induction of the trimolter and hormonal secretion of the corpora allata were examined. The results are as follows:
1. When the larvae being controlled by the gene of Lm^e were treated with high temperature, they often became trimolter due to the decrease of hormonal secretion in corpora allata controlled by the brain.
2. The inductivity of trimolter with high temperature treatment was affected by the rearing temperature after the treatment, being lower in 20°C than in 25°C.

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Floral initiation was greatly delayed in four sorghum cultivars [Sorghum bicolor (L.) Moench] and slightly delayed in three other crop plant species (Zea mays L., Helianthus annuus L., and Gossypium hirsutum L.), when grown in atmospheres containing approximately 1, 000 ppm CO₂ as compared with plants grown in ambient air. In previous tests, hastened floral initiation had been attributed to enhanced production of photosynthate, a theory which was not confirmed by the present study.

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To control the leaf temperature by means of setting the desired value of the leaf temperature, the feedback control of leaf temperature was carried out in a growth cabinet: The leaf temperature was detected by the use of a microthermistor which was inserted into the cotyledon of the Cucurbita seedling. This leaf temperature was used as the feedback signal for the temperature control system in the growth cabinet. In this system, air was used for heat transfer, and the program control of the leaf temperature was made possible by setting the desired value.
For the analyses of the response characteristics in the leaf temperature control, conditions of light, air humidity and air movement were changed to give the disturbances to the leaf temperature control.
From the results, the following points were ascertained.
1) In this system, the ramp response in the feedback control of the leaf temperature conformed well to the desired value. At the leaf temperatures of 10°C, there was no difference between the leaf and air temperature in darkness. With the increased temperature, however, the air temperature became higher than the leaf temperature.
2) When the leaf was irradiated to an intensity of 31 mW/cm² by an incandescent lamp, the leaf temperature rose, while the air temperature fell. In proportion to this fall in air temperature, the leaf temperature settled within at least 15 min. The effect of this disturbance of irradiation on the leaf temperature control was larger in lower temperature condition than in higher temperature condition.
3) When the air humidity was changed rapidly from 60% to 80% and from 80% to 40%, the leaf temperature control was disturbed. The effect of the air humidity change on the leaf temperature control was larger under higher temperature condition than under lower temperature condition. The leaf temperature settled within 10 min.
4) The air movement decreased the difference between the leaf and air temperatures and made the settling time short.

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A new method is reported for automatic program control of environmental conditions by the feedback of response to a self-regulating system of environment control. As an example of the achievement of this method, an air temperature fitting to the growth rate of leaf programmed at 2.28mm per hour was determined automatically and 29°C was obtained as the answer.

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1) Dutch iris bulbs (cv. Wedgwood) stored at 13, 8 or 2°C for about four months just after harvest and planted at the experimental farm at the end of September showed dormancy, while those stored at 17 or 30°C exhibited normal growth.
2) Bulbs stored at 20°C from the beginning of June showed a rapid increase in the length of the first leaf after the beginning of August, while those stored at 10°C remained in a state of rest and initiated new bulbs inside the mother bulbs. This phenomenon is quite similar to pupation of freesia corm.
3) The higher the temperature and the longer the duration of the curing period, the higher the percentage of sprouting among lots exposed to 20, 25, 30 or 35°C.
4) Heat curing at 30°C was slightly more effective than that at 20°C for six week storage periods after harvest. However, heat curing at 30°C was less effective than that at 20°C, if the curing period was prolonged for more than 8 weeks.
5) A larger heat sum is necessary for flowering in forcing than is needed for sprouting. Bulbs stored at 20°C from June 9 required about 40 days prior to cooling at 8°C for 49 days for a high percentage of flowering.
6) Application of regulators (benzyladenine, gibberellin and ethephon) were examined for their effects on the sprouting of bulbs. There was no difference between treatments with benzyladenine or gibberellin given prior to or after heat curing, while ethephon was only effective when given after heat curing.

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