Water content in various body parts of the barnacle, Tetraclita squamosa japonica, together with temperature conditions of the environment and of animal body, were measured during the period exposed to air at the time of ebb and compared between the individuals living at high and low levels. The amount of extra-visceral water and the water content in the shell were larger in high level individuals than in low level ones ; although the water contents of the soft parts were of the same degree among the individuals of both levels, the rate of decrease during the exposed period was far slower in high level animals. All these facts show higher adaptation of the high level individuals than low level ones to the prevailing environmental conditions-high temperature and strong desiccation. The fact that the temperature inside the body of high level individuals was maintained constant during long exposure time in severe solar radiation, irrespective of remarkable rising of air and the rock surface temperature, must also be noticed.
1. Distributional pattern of the Carex kobomugi OHWI population in Hamasaka Sand Dune, Tottori, was investigated and the clump size of it was estimated by making use of MORISITA's Io_<(p)> index and the values of Io_<(s)>/Io_<(2s)>. 2. Individuals of ahoot were found to be distributed contagiously forming the clump, and two scales of pattern were found in this population. The scales of the pattern were about 1/32 and 1/2 square meters. 3. The correction method of the frequency distribution of clump size is described to remove the error based on the edge effect of quadrat. It is found that this method is of use with a reasonable degree of accuracy. 4. The smaller scale of clump size is ascribed to the mode of frequency distribution of clump size ; in other words, the primary scale of pattern shows the frequent or common clump size. The larger is due to the maximum total clump area, that is, it shows the maximum of the product of the number of clumps and the area of clump. The frequency distribution of the clump size of the population follows the lognormal distribution. As these two scales of pattern are determined in relation to the lognormal distribution, in such population that the frequency of clump size shows the lognormal form there may be two scales of pattern in any other species population. If the quadrat size is small, the secondary scale of pattern may not be found. 5. MORISITA's Is technique may be applied to the population which has not the normal frequency distribution of clump size.
MORISITA((1961) offered a census equation adjusted to the deflection, caused under the effect of multiple collisions with a snap-trap, from a linear regression following the routine equation C_n=(N-S_<n-1>)p, It is coincident with z=k'(N_<0-y>) proposed by LESLIB and DAVIS (1939). Eleven field examples for removal and marking works with each one single-catch trap set at a station have been examined to calculate under what condition the routine equation should be replaced by z-equation and its like. A much greater effect of such agents would be supposed in the marking method than in the removal, but I have reasoned that the marking record is affected in different ways according to different trap-response types (isoresponsive and two kinds of alloresponsive) of the population concerned ; a modified equation presented in place of z-equation seems to be suitable for the π>p type, and the influence on the decidedly isoresponsive type can be considered negligible even under the condition that the catch relative to effective trap number is pretty large, or as much as 0.73 shown in an example. Through the treated examples, excepting each one of the isoresponsive and the π>p type, the routine equation has proved to suffice for their records provided the catch rate is 0.40 or less. In an uncertain π>p example, however, a non-negligible effect would seem to have occurred at the catch rate of 0.49. Setting of each 3 snap-traps, simulating each one multiple-catch trap, at a station will serve to make the equation much sounder.
Experiments were carried out to examine the effect of various diets and mating on the egg-laying habit and phototaxis of the black carpet beetle, Attagenus megatoma at 30℃, 50〜60 per cent R.H. Duration of the pre-oviposition period of four days was not affected by the kind of diet and mating. In the continuous pairing, the duration of net-oviposition period of the adults given with water or honey were prolonged more than those of the adults deprived of food, but an increase in the oviposition period was only noted when the adults were given honey in the limited pairing. In the continuous pairing, the duration of the post-oviposition period was seven to eight days except the adults fed on honey. Unmated female did not deposit eggs, but some individuals deposited unfertillized eggs when fed on honey. When water was given, there occurred a significant increase in fecundity, and when given honey there was a further increase as compared with unfed adults in both continuous and limited mating. However, in limited pairing, adults deposited less eggs than those of continuous pairing in all cases, repeated pairing is therefore necessary for the attainment of full potential fecundity. Effects of water and honey upon the increment of the life span except the males of limited pairing that were given water were significant in all cases. Change of response to the light occurred earier in unmated adults than in mated ones. Reversal of phototactic response occurred a few days earlier in the female than in the male. When honey was given, and in most cases, water supply increased the duration of negative response as compared with those deprived of food. Egg laying curves shown by the adults provided with the same kind of food are almost the same regardless of the duration of pairing. From the results described above discussions were made on the status of Attagenus megatoma from the viewpoint of adaptation to the indoor life by marking a comparison of the ovipositional habit among dermestid species. It was concluded that Attagenus megatoma is in a transitional process of adaptation to the indoor life.
OHGUSHI, Ryoh-ichi and Yoko SAITO (Kyoto Univ., Kyoto) Ecological notes on the stream drifts in River Ukawa. Jap. J. Ecol. 13,28-35 (1963). Studies on the stream drifts in River Ukawa, Yosa Peninsula of Kyoto Prefecture were carried out in the summer of 1957 and 1960. The surpended materials flowing down in the river water were distinguished as follows ; sand and silt, organic debris, aquatic insects, exuviae of aquatic insects, fishes in young stage, and fragments of plants and terrestrial insects. Generally, the sand and debris occurred most frequently. Aquatic insects appeared in the stream drifts chiefly consisted of the nymphs or larvae of mayflies and midges. The contents of the collected materials were different according to the mesh of the collecting nets. Silt, debris and small insect larvae were caught by fine net (GG 72). On the contrary, the rough net (GG 40) caught the sand, leaves of tree and large insects. The volumes of collecting materials by the rough net were larger than that by fine net. The flowings of aquatic insects increase in night, but the daily rhythmic variations were not seen in the other materials. The volume of sand and debris contained in the water were varied with the parts of the river. The water in the upstream of the pool contained sand more of than that in the downstream. From the results of the above-mentioned investigations, ecological meanings of stream drifts are discussed.