13. Wiesnerella denudata(MITT.)STBPH., cf. HORIKAWA 1952,Jour. Sci. Hiroshima Univ. Ser.B, 2-6 : 72 Wiesnerella denudata belongs to one of the largest thallose hepatics and is usually found in the mountainous region. The species was originally described by MITTEN as Dumortiera denudata based upon the specimen which was collected at Oriental Himalaya. STEPHANI afterwards (1899) transferred it to Wiesnerella. At present there are 161 packets of specimens of this species from various sources in our herbarium. In this paper it will be reported for the first time from the Prefectures Yamanashi (1), Fukui (2), Shimane (5), Nagasaki (1). Additional new localities of the species are the Prefectures Shizuoka (3), Mie (1), Nara (2), Wakayama (2), Hiroshima (1), Yamaguchi (1), Tokushima (4), Ehime (1), Kochi (15), Fukuoka (3), Oita (3), Kumamoto (7), Miyazaki (3), Kagoshima (1). Map 13 in the text is based on 168 locations, among which 55 are new additions and 113 were previoushly known. From the map it may it may be noticed that the northernmost limit of distribution of the species is Ichinoki-mura(37°44′L.N.)in Fukushima Prefecture, In so far as the present state of our knowledge is concerned, this species is distributed in two regions(viz. southern part of Japan and Formosa). The results of macrofrequency in each district are shown in table 14. As seen in this table, the values of macrofrequency in the districts of Japan and Formosa are generally equal, and the distribution-fall is distinct between Kiushiu and Formosa. According to our present knowledge, the highest elevation of this species is on Mt. Ishizuchi in Shikoku where it was found 1110 m above sea-level and its maximum luxuriance is in evergreen broad-leaved tree zone. Geographic distribution. Japan , Formosa, Hawaii, Java and Himalaya. [table]
The writers studied the behaviours of A. Yamamai ♀×A. Yamamai ♂ and A. pernyi ♀×A. Yamamai ♂ all through the night with the purpose to know their generative characteristics. It was found that most of the moths begin to copulate late in the midnight from 1 a.m. to 3 a.m. and end just before dawn viz. from 3.30 a.m. to 4.30 a.m. As regards A. pernyi ♀×A. pernyi ♂ and A. Yamamai ♀×A. pernyi ♂, observation was made every 30 minutes, with the result that most of them start copulation in the midnight from 11 p.m. to 4 a.m. and terminate in the dusk, viz. about 7 p.m. of the successive day. The duration of copulation in the former two groups(A. Yamamai♀×A. Yamamai♂ and A. pernyi♀×A. Yamamai♂)was nearly two hours in average, while in the latter two groups(A. pernyi♀×A. pernyi♂ and A. Yamamai♀×A. pernyi♂), it was about 14-16 hours, with wide variations among the individuals. The longest records of duration in A. pernyi ♀×A. pernyi♂, A. pernyi ♀×A. Yamamai♂ and A. Yamamai♀×A. Yamamai♂ were 26 hours 13 minutes, 24 hours 21 minutes, 6 hours 28 minutes and 8 hours 25 minutes respectively, while the shortest records of the abovementioned four groups were 12,5,17 and 5 minutes respectively. Although one copulation in one night is the general tendency among them, one of the authors has once witnessed a pair that copulated twice in a single night. Such a case, of course, is very rare. Among A. pernyi, however, there are a few that copulate as frequent as for three successive nights. Needless to say, the impotent moths die witbout any sexual behaviour.
According to the writer's microscopic observations from the latter part of July of 1954 to the early part of August of the same year, the male A. Yamamai moth ejaculates in the Bursa Copuatrix of the female moth about half an hour after copulation and the shift of the spermatozoon to the female receptaculuin seminis follows for 6-7 hours thenceforth. The ejaculation of the male A. pernyi moth, on the contrary, is 25 minutes after copulation and the shift of the spermatozoon to the receptaculum seminis is 4-5 hours after the incident. In comparison with the rapid process seen in Bombyx mori, in which the ejaculation takes place 15-20 minutes after copulation and the shift of the spermatozoon is only one and a half hours henceforth, the extinguished retardation should be considered characteristic to these wild silkworms.
The results of investigation on the natural distribution of Camellia sasanqua(an endemic tree of Japan), are shown in figure 2. The northern limit of its natural distribution is Ikinoshima Isl. (about 33°15′N.L.)in Nagasaki prefecture and its southern limit is Yakushima Isl.(30°15′N.L.)in Kagoshima prefecture. The fact that sasanqua is not found in the southern regions beyond Yakushima Isl. seems to be attributable to the geohistorical causes. In southern Kyosho, it thrives so densely that it often appears as the dominant-species of forest communities 300-600m high above sea level, especially in the Distylium racemosum forests. And it occurs rarely in such Abies firma forests as 900m high above the sea level. In the islands or peninsula of north-eastern Kyushu surrounded by warm currents, it is found comparatively abundantly. Generally speaking, sasanqua is more abundant on mountain sides where the soil is well drained, more so in the third stratum than in the second of the forests ; it is little in forests along ravines. It general it seems that the trees are thinly scattered in the districts near the northern limit habitate. As the climatic factor, "The index of warmth"of northern habitats was recognized as 130°-135°. Therefore, it may be said that this tree is closely related to the subtropical trees from"The index of warmth".
In a previous article, the author mentioned that three species of barley aphids, Aphis maidis, Macrosiphum granarium and Rhoparosiphum prunifoliae segregate allopatrically on a single shoot of barley. Of them the first mentioned species is found on top leaf blades, the second on basal leaf blades and the last on intermediate leaf blades(ITO, 1952,'54). In the present paper, the results of the survey on their host plants conducted in 1954 are summarized as follows : 1. In summer, Aphis maidis was found on nine species of the Gramineae and on one species of Cyperaceae, being especially abundant on Setaria viridis, Eleusine indica and Zea Mays. 2. Macrosiphum granarium was found on 13 species of the Gramineae and on some unidentified Cyperaceaus grasses. 3. Rhopalosiphum prunifoliae was found on ten species of the Gramineae and on some Cyperaceous grasses. This species is rarely found on crops and weeds belonging to the Gramineae in midsummer. SUENAGA(1953)reported that it often infests the roots of the uplane rice plant. 4. Setaria viridis was attacked by Aphis maidis, but it was an important host to this aphid. The aerial parts of the rice plant and Eragrostis Niwahokori were attacked only by Macrosiphum granarium. In general, Aphis maidis preferred Setaria, Eleusine, Digitaria and some field gramineous crops, while Macrosiphum granarium preferred Digitaria, rice plant and especially small gramineous weedss in the cultivated field such as Alopeculus, Poa and Eragrostis. Such speciality in host preference agree with the collections by PATCH(1938). 5. While Macrosiphum granarium and Rhoparosiphum prunifoliae were found on 15 varieties of wheat, barley, rye and oat, Aphis maidis was found on only barley(Table 3). 6. As mentioned above, the three species of barley aphids which segregate to different parts on a single barley shoot, also segregate to different suitable host plants in spring and summer, though they show some overlap in host preference. The former segregation can be considered as an example of the second synusial system of IMANISHI's theory of habitat segregation and the latter segregation one of the first synusial system. 7. Some host plants of these aphids which PATCH(1938)had not recorded are added by the present author.
The present paper deals with studies on the ecology and taxonomy of Frullania moniliata occurring in Japan. Basic materials in this work consist of 268 packets collected by Messrs. H. ANDO and S. NAKANISHI, and 54 packets collected by the writer. 1) From the ecological studies the species can be subdivided into several ecological forms such as Nearly round leaf form(fig. 2,A-E), Round leaf form (fig.2,F-J), Alpine form (fig. 3), Patent lobule form (fig. 5), Corticolous form and Rupicolous form (Table 1). 2) These ecological forms are included in the category of Frullania moniliata subsp. obscura VERDOORN. 3) Fr. moniliata subsp. obscura fo. parva VERD. (1930) and var. rotundata HORIKAWA(1935)are included into the synonymy of the subsp. obscura. The writer expresses his gratitude to Prof. Dr. Yoshio HORIKAWA for his kind guidance and thanks are also due to Ass. Prof. H. SUZUKI, Mr. H. ANDO and Mr. S. NAKANISHI of the Botanical Institute, Faculty of Science, Hiroshima University, for their suggestions and assistances in the investigation.
The following types in natural population of a food infesting acarid mite, Carpoglyhus lactis L., which lives in the miso brewing tank are found by the occurrence probability method^<2,3>) Ad type……Adults dominant. A・N type……Adults and nymphs dominant. N type……Nymphs dominant. L type……Larvae dominant. L・E type…Larvae and eggs dominant. E type……Eggs dominant. X type……Adults, nymphs and larvae are almost equal in number, but the egg is few in number. Y type……Every fourth stage is almost equal in number. From the number of eggs contained in an adult female of the mite, the populations may be classified into 5 types(Fig.1). By combining these two groups of population types, it becomes clear that there are two courses from a population which is mainly formed by the younger stage to that formed by the older one. One leads to the Ad-B population, the other to the Ad-A population(Fig.2), the former is the progressive course, and the latter is the decaying one.
To study the injury of seeds by soaking in water, the writer used those of Phaseolus vulgaris L. The seeds were soaked in the tap water passed through the ion-exchange resin and kept at temperature of 25℃. It was shown that soaking injury is influehced by the amount of moisture which a seed contains before soaking in water. The harmful effect by subsequent germination considerably increased in the seeds dried in the decicator with calcium chloride at the room temperature. On the other hand, it decreased for the seeds that absorbed moisture in the moist chamber. L.V.BARTON(1950,1952)reported that the water absorption rate of the bean seed is related to the soaking injury. In this experiment, all of the seeds contained the same quantity of moisture after soaking in water for 4 to 6 hours, but the dry seed absorbed a greater quantity of water than the wet one during soaking. It seems that the amount of moisture which a seed contains before soaking has relation with the quantity of absorption of water during soaking and this results in afecting the subsequent germination of the seed. Soaking injury differs according to the condition of preservation of the seeds.
The outbreak of the "yellow dwarf" disease of soy bean plant caused by the soy bean nematode, Heterodera glycines, was commonly observed in the volcanic ash soil in Hokkaido. In 1954,this disease occurred in the peat soil at Ebetu, Hokkaido. A survey was made in this field, where three patches of disease appeared. Soy bean plants and soils taken from the inside and outside of these patches were examined with regard to the growth of plants and the nematode populations respectively. It was thought that this disease is due to the increased nematode population in clayey loam rich in humus having been mulched on peat soil surface.
1. The climate of North area in Yunishikawa shows intermediate figures lying between the climate of Japan Sea type and Pacific coast type. 2. Specific composition on the surveyed ares consist of Japan Sea element and Pacific element half and half. 3. Climax beach forest on the area lies between(Saseto-Fagetum crenatae)which is typical in Japan Sea region and(Pleioblasteto-Fagetum crenatae) in Pacific coast region. The most dominant species in the forest floor is Carex Morrowii, instead of Sasa which is usually found in Japanese beach forest, that is to say, the vegetational type of forest floor is not the Sasa-type but carex-type. 4. On rocky cliffs or on ridges, the forest of Pinus pentapkylla with Thuja Standishii develops. 5. After surveying, the following associations are recognized. A : Saseto-Fagetumcaricetosum B : Saseto-Fagetumaesuletosum C : Rhodoreto-Thujetumilicietosum.
Homing behaviors of two species of limpets, Siphonaria japonica and Patelloida saccharina lanx, were studied at the sea shore of the vicinity of the Seto Marine Biological Laboratory. These two species show homing behavior in summer. The distances of locomotion are generally limited within 5-10cm. When returning home, many of them creep along the tracks made during their leave, but some of them can return without following the same track. When they are translocated artificially 5,10,15cm apart from their homes, some of them can return, the rates of which are shown in Table 2. In these experiments, many individuals took direct courses to their homes. From these observations, it may be considered that these species can return home by following the tracks first made on the one hand, and by memory of the topographical features on the other. The latter seems to be more and more established with the elapse of time since the animal inhabits a certain site.
The epiphytic diatoms on the cultured laver were observed in two laver-fields, Kakijima, Korea in 1942 and Tokushima, Tokushima Pref. in 1953. The results are as follows : Diatoms begin to occur just before becoming the lowest water-temperature and develop in abundance during the culture period of laver. So that diatoms almost don't occur on the young frond of laver. The rain seems to accelerate the reproduction of the diatoms. The thriving of diatoms in abundarce are seen in the lower levels of the tidal zone than in the upper ones. In order to protect from diatoms, therefore, the twigs for laver-culture must be hung up to 4 hours exposed(in the spring tide)level at the period of the lowest temperature of water.