How the plant acts as an entity to adapt itself to the ever changing surroundings is a problem of fundamental importance[1,7]. The problem has been put forward to the botanists by the theory of Michurin and Parlor, both of whom have proved with their own experiments that living beings are in unseparable unification with their environment. As we know, along the evolutionary steps that lead lower and simpler forms of life to higher and more complicated ones, the more the differentiation of functions among the constituent parts, the more the needs for closer coordination among them. Hence, the plant must integrate the various processes in metabolism conducted in its various parts into a united whole in order to "equilibrate" with external changes. To put it more concretely, in a plant body which is consisted of innumerable cells, each cell being entirely enclosed in a rigid wall, intimate coordination among its physiological functionings, proper responses to local and transmitted stimuli, timely translocation of manufactured food and efficient distribution of absorbed minerals must be effectively maintained. The attempt to solve these problems of plant integrity is to try to synthesize the individual physiological phenomena on a common ground, to realize the interlocking connections involved, and, finally, to serve as a more effective guide in controlling nutrition, growth and development in plants. It has been generally accepted among the botanists that the living cells constituting a plant are interconnected by protoplasmic threads (Plasmodesmata) so that the plant is a definitely correlated entity of interconnecting protoplasts (Symplast)[42]. So far evidences of protoplasmic continuity in plants mainly come from anatomical observations on dissected tissues. Based upon these facts, plasmodesmata have bean suggested as channels of translocation of organic solutes. Consequently, the symplasmic nature of plant has been incorporated in Münch's theory of mass/low of organic solutes. Conduction of stimuli has been regarded as a second function (Haberlandt)[13]. Direct evidences, however, for any such role of plasmodesmata are wanting. On other occasions, the presence of plasmodesmata has been ignored or considered irrelevant. Lund et al[50], in their investigations on bioelectric fields in plants, have never taken into consideration how such protoplasmic continuity would affect potential and current distribution in plants. Lundegardh[40], in his investigation on the translocation of salts through roots, does not believe that it is necessary to visualize a symplast to account for this process. The cited examples are sufficient to indicate that we are altogether uncertain of the role of plasmodesmata in the physiological functionings of plants and due attention has not been paid to them.

This paper presents some preliminary results of the experiments conducted in 1953 and 1954 on the temperature and duration requirements for vernalization of wheat varieties cultivated in the East China. In determining the requirements for vernalization of those varieties, the method described by Ivanov (1951)was used. Seeds free from any disease, were selected for uniformity. They were wrapped in gauze and tagged with cloth-labels marking the variety, temperature and duration for vernalization. Prior to the vernalization-treatments, the seeds already prepared were soaked in water at room temperature for 24 hours. The seed-moisture was brought approximately to 45% before the seeds were made to germinate at 10℃ (but without- the radicle penetrating the coat). During vernalization the seeds were kept at 0-3℃ (or 2-4℃ as in 1953), 5-8℃, and 10-12℃ for 5 to 45 days at an interval of every 5 days. Non-vernalized seeds served as controls. Both the vernalized seeds and the controls were sown on the same date in spring when the soil temperature had become higher than 10℃ and the daily possible sunshine longer than 12 hours thereafter. The temperature and duration requirements of the different varieties for the Completion of the vernalization process were judged from the earing dates and their unifomity. Results thus obtained are briefly summaried as follows; 1. The temperature and duration requirements for vernalization have been worked out for 104 varieties. In accordance with their characteristics in response to vernalization-treatments, these varieties may be divided into 3 groups: (1) Spring type Controls eared as normally as the fully-vernalized plants. Those from seeds vernalized for different lengths of periods showed no significant difference in earing dates. In most cases, acceleration in earing due to vernalization was 0-2 days, indicating that the vernalization-stage was very short, probably less than 10 days. 27 varieties belonged to this type (Tab. 1. Var. no. 1--27). (2) Semi-winter type The optimum temperature for vernalization of these verieties was 5-8℃. In accordance with their response to vernalization treatments. varieties of this group may be farther subdivided into 2 groups: Group A. This group was distinguished in its wider range of temperatutre for vernalization process. At a temperature higher than 10℃, vernalization process still proceeded at some moderate rate. Acceleration in earing due to vernalization treatments was 4-11 days. There were 8 varieties belonging to this group (Tab. 1. Var. no. 28-35). Group B. Controls failed to ear. Temperature higher than 10℃ was probably too high for the normal process of vernalization. Vernalization-stage at 5-8℃ was 25-30 days in length, varying with varities. 23 varieties belonged to this group (Tab. 1. Var. no. 36-58.). (3) Winter type Controls failed to ear. Temperature higher than 10℃ was too high for the normal process of vernalization. Vernalization proceeded slower at 5-8℃ than at 0-3℃. The duration for the quickest completion of vernalization at 0-3℃ was 30-45 days, varying with varieties. 2. The varietal characteristics in vernalization-stage was found to be closely connected with the winter conditions under which the varieties had been formed and cultivated. Varieties grown in the regions lying between January isotherm -2℃ and 0℃ were mainly of winter type; those cultivated in the regions south of January isotherm 4℃ were mainly of spring type. Varieties distributed in the regions south of January isotherm 0℃ and north of January isotherm 4℃ were mainly of Semi-winter type (Tab. 2).

A diagram showing the life cycle of Porphyra tenera Kjellm. was published about a year ago in this journal[1]. Further studies have shown that the Conchocelis-phase liberates its conchosperes only between 15℃ and 20℃[2]. It follows that the summer and autumn forms of the dwarf porphyras which appear only in water temperature higher than 20℃ cannot arise from these spores; the two lines leading from the conchospores to these two forms of the dwarf porphyra must therefore be deleted. This and a few other minor points make it necessary to prepare a revised diagram which is herewith presented.

Commercial cultivation of haitai (Laminaria japonica Aresch.) has been carried on at Tsingtao since 1952. Although production has been stepped up quickly in the last few years, the industry has not been advancing as rapidly as it is desired. This is due to the existence of several problems inhibiting the progress of the industry. One of these concerns with the detrimental effect of various algal growths, particularly Ectocarpus, Ulva and colonial diatoms such as Licmorphora, on the growth of the Laminaria gametophytes and the development of its sporophytes. In the haitai cultivation at Tsingtao, spore collection is effected in late October through November when surface sea water temperature has already dropped down to below 20℃. It takes from two to three weeks under good conditions, and much more time under less appropriate conditions for the completion of the growth and developmental processes from spores to sporophytes. During this period, Laminaria has the least ability of competition against algal weeds, and it is in the same period when Ectocarpus and various other algal weeds are most vigorous in their multiplication. Therefore, soon after the setting of the collectors with the Laminaria spores in the sea, spores of these weeds quickly adhere to these artificially set substrata, and before formation of the Laminaria sporophytes has been effected, these weeds have already grown to such sizes as to choke the microscopic gametophytes, prohibiting them from receiving sufficient light to satisfy their growth and developmental requirements. Thus, formation of haitai sporophytes is greatly delayed or even totally inhibited, resulting in greatly decreased production or in extreme cases, total failure of the crop. Solution of the problem has therefore become one of the keys to the further development of the haitai cultivation industry. A means to solving this problem has now been devised by collecting the spores in early summer instead of middle or late autumn, cultivating the spores and subsequently the gametophytes and the sporophytes in a temperature lower than 20~C (temperature actually employed about 10℃) during the summer, and growing the young sporophytes in the open sea soon after the surface sea water temperature drops down Lo about 20℃. By means of this change in the time of spore collecting and the cultivation of the young sporophytes in artificially lowered temperature in the summer, the sporophytes, when taken out from the cold room and cultivated in the sea in middle or late autumn, are already several millimeters in size and are able to grow much faster and more vigerously than Ectocarpus or the other algal weeds. Consequently, these weeds are unable to grow on the same collectors, or if they do so, are not able to affect the growth of the Laminaria. The method employing summering young sporophytes at low temperature not only solves the problem of the competition of various weeds, but also results in an increased production. When compared with the control experiment, the yield is a little more than double (208:100). This is due to the fact that under the special treatment, the sporophytes have two more months of growth than those cultivated by the usual method. By using the special method, laboring conditions have also been improved, since segregation of the young sporophytes could then be conducted in December and early January instead of late January and February when surface sea water temperature approaches freezing point. Moreever, costs involved in summering haitai sporophytes could also be minimized or even totally eliminated. Possibilities in commercial cultivation of haitai to the south of Tsingtao and of Undaria pinnatifida in East China coast (especially Chekiang) by employing the new method have also been suggested.