1. If we divide the young petiole into certain zones with equal intervals, each zone elongates to a different extent; the result may be summerized in three types: Type a, in which each zone in the petiole elongates nearly equally. Type b, in which the upper zone of the petiole shows a conspicuous elongation. Type c, in which the lower zone of the petiole shows a conspicuous elongation. 2. It is assumed that in type a, there is no important influence of the meristematic part upon the elongation of the petiole, but in types b and c, the petiole elongates itself through the influence of the meristematic part situated in the uppermost zone of the petiole. 3. Among these three types, typeb is the most common, in which their elongation ceases from the lowest zone upwards. 4. The energy of elongation is least in the lowest zone in each type. 5. In a full-grown petiole, even if the uppermost zone shows the maximum elongation, the zone does not always show the maximum elongation among divided zones through the whole growing period; on the contrary, at a certain period in the course of the elongation other zones also show the maximum elongation.
Among the edible agarics in Japan, Matsutake (Armillaria Matsutake S. ITO et IMAI), Shiitake (Cortinellus Berkeleyamus S. ITO et IMAI=Cortinellus Shiitake P. HENN.) and Nameko are the most common and highly prized. On the taxonomy of the former two species, the writer with Prof. SEIYA ITO discussed in detail in the previous paper. Now the present short paper was prepared on the last fungus. Nameko is a common local name, applied to the agarics which have viscid or gelatinous pileus, and in which at least the following, six species are included, viz. Collybia velutipes, Collybia Nameko, Pholiota adiposa, Pholiota mutabilis, Flammula lubrica and Flammula lenta. After the detailed remarks on the morphological characters of each of these species, a special attention was given to Collybia Namelco, which was described by Dr. TOKUTARO ITO in 1929. The writer obtained the fresh materials of the fungus from Hokkaido and Yamagata-Prefecture, which is popularly known as “Nameko” in these districts and also the “Nameko” fungus canned for sale from Fukushima-city. It was proved that they are identical in species, and it belongs to the genus Pholiota. After the careful comparison of our fungus with the description of Collybia Nameico, it was concluded that they are identical with each other. Naturally, the name Collybia Nameko should be changed to Pholiota Namcko (T. ITO) S. ITO et IMAT. The revised diagnosis of the Nameko-fungus in the strict sence was given. The fungus is easily distinguished from other members of the Truncigeni-section of the genus Pholiota by the gelatinous nature of the pileus, stem and annulus, and by the smaller spores, obtuse at both ends, as well as by the absence of cysticlia.