STUDIES ON THE SEASONAL CHANGES OF GERMINAL CENTERS OF SPLENIC LYMPH NODULES AND OF BLOOD LYMPHOCYTES OF DUCKS

가압비장임파여포배중심(家鴨脾臟淋巴濾胞胚中心) 및 혈액내(血液內) 임파구(淋巴球)의 계절적(季節的)인 소장(消長)에 관(關)한 연구(硏究)

For the purpose of investigating seasonal changes of germinal centers of splenic lymph nodules and of blood lymphocytes of ducks, the spleens of 8 ducks from a flock were observed histologically every season; 2 cases in spring (March and April), 2 in summer (July and August), 2 in autumn (October and November) and 2 in winter (December and January). Blood cells of 8 ducks from the same flock also were counted during the summer (from July to August) and autumn (from October to November) The results obtained were summarized as follows: 1. There were seasonal changes in the germinal centers of lymph nodules, that is, the germinal centers were formed in spring and disappeared in autumn. In summer these were at the stage of transition from formation in spring to disappearance in autumn. In winter, on tile other hand. the process was reversed from the stage of disappearance in autumn to the stage of formation in spring. 2. The germinal center of splenic lymph nodule was encapsulated with a fibrous capsule which disappeared concommitantly with its germinal center. 3. The percentage and absolute value of lymphocytes in autumn were higher than those in summer, the fact that seemed to be not in agreement with Flemming's view that the lymphocytic clear germinal center may be functionally at the stage of lymphocyte formation, but in agreement with Maximow's view that the large lymphocytic clear germinal center is functionally at the stage of resting and medium-sized lymphocytic germinal center may be functionally at the stage of lympocyte formatiom.