Histopathological studies were carried out on skeletal muscles of 1, 723 individuals consisting of embryos, and abnormal and normal chicks which had been collected on the days of hatching during the same year. Muscle lesions were readily found in 360 (21%) of the specimens at low-power magnification microscopy. Muscle fibers in the lesions showed mainly focal swelling, focal rarefaction with a lack of myofibrils and sarcoplasm, and the appearance of basophilic substance. Some of the lesions were associated with mild reactive changes in the interstitial connective tissue. Based on the findings of rarefied areas in the affected muscle fibers, a pyesumption was made that these muscle lesions might have occurred in immature muscle fibers and be regarded as a hypoplastic change.

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The fluorescent antibody (FA) test was applied to the serological identification of the Mycobacterium avium-M. intracellulare complex in comparison with the agglutination and complement fixation (CF) test. The results are summarized as follows: (1) As a serological method of identification, CF test was a little less effective than the agglutination test. The agglutinin adsorption was necessary for about half the number of strains of the serotypes examined. A few cross reactions were eliminated by the use of CF antigen purified with chloroform. Complement-fixing substances were detected as an anthronpositive spot by thin-layer chromatography. (2) The indirect fluorescent antibody test (IFAT) was successfully applied to the identification of organisms of the known serotypes, as well as the unknown primary cultures of swine origin. (3) Such cross reactions as observed sometimes in the agglutination and CF tests did not appear in the IFAT, even when unabsorbed immune sera were employed in this test.

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Neurohistopathological investigation was carried out on 224 individuals which consisted of 52 not pipping embryos, 49 pipping embryos, 17 culled chicks, and 106 weak chicks and which had been randomly collected on the day of hatching. Forty-three individuals had histological lesions characteristic of avian encephalomyelitis. The percentage incidence of this disease was 11.5% in the not pipping embryos, 20.4% in the pipping embryos, 35.3% in the culled chicks and 19.8% in the weak chicks. The lesions were composed of central chromatolysis or tigrolysis (axonal reaction) of large motor nerve cells in the brain and spinal cord. The reactive changes were negligible. In addition, the same degenerative alterations as seen in the large motor nerve cells were observed in ganglion cells of the spinal ganglion. These changes were considered to be equivalent to the lesions of the brain and spinal cord. The results obtained give a morphological proof of the egg transmission of avian encephalomyelitis, which has been presumed to be possible since the first reports on this disease.

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Resin and neoprene cast preparations of the kidney of 56 fowls were examined. The arterial supply to the lobus and lobulus is described. Relationships among the renal artery, the portal and venous circulation, and the ureteral system are investigated. The A. renalis cranialis distributed in the Divisio renalis cranialis of the kidney is divided into three or four primary branches after arising from the Aorta abdominalis. The A. renalis media supplying the Divisio renalis media arises from the A. iliaca interna with the A. renalis caudalis at almost the same site. The A. renalis caudalis running to the caudal direction supplies four or five branches to the dorsal and caudal part of the Divisio renalis caudalis. The branches of the A. renalis which extend to the renal parenchyma are named A. interlobaris, A. intralobaris and A. intralobularis in relation to the lobus and lobulus. The glomerular capillaries are classified into three types on the basis of vascular anastomosis and ramification. The Vas efferens is longer than the Vas afferens. If rums toward the periphery of the lobulus and gives off two to five branches which communicate with the renal portal vessels. The extraglomerular arterial circulation is classified into two types: (1) Ludwig's vessel and (2) the direct glomerular bypass, which arises from the intralobular artery in close relation to the Vas afferens and anastomoses with the renal portal circulation. The vascular system and the ureteral system are arranged in the lobulus of two types with the hard and fast rule.

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The mechanism of anemia in feline haemobartonellosis was examined with 15 cats as experimental animals. Haemobartonella felis appeared on erythrocytes 3 to 18 days, or 6.7 days on an average, after inoculation. The erythrocyte count, hematocrit and hemoglobin decreased in value in the 15 cats over a period of appearance of H. felis on erythrocytes. They tended, however, to return gradually to their previous levels immediately after the disappearance of H. felis from erythrocytes. On the contrary, the osmotic fragility of the erythrocyte showed a marked increase immediately following the appearance of H. felis, but it showed no recovery even when the parasite disappeared from erythrocytes. The direct Coombs test became positive in all the animals for 15 days on an average after the first appearance of H. felis on erythrocytes. Erythrophagocytosis by mononuclear cells or rarely by neutrophils was observed in blood smears of 11 animals for 19.5 days on an average from the first appearance of H. felis. From these results, it is conjectured that parasitized erythrocytes may probably be sequestrated by reticuloendothelium of the spleen or some other organ, but that some of them may return soon to the circulating blood by getting free from the parasite in spite of some damage caused by the parasite. What damage H. felis does to erythrocytes will be studied in future.

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In chickens infected bxperimentally with Eimeria maxima and E. necatrix, contractile activity of the digestive tract was studied by means of Magnus' method. Intestinal tissue specimens were examined for response to acetylcholine when they were of coccidiosis during the severe symptomatic and recovering period. E. maxima was found in the deep portion of subepithelial tissue in the villi of all the parts of small intestine. It caused a severe symptom in the host on the 6th day postinfection. Contractility to acetylcholine was different among three parts of the small intestine. It was reduced remarkably in the anterior part and mildly in the middle and posterior parts of the small intestine. On the 5th day after inoculation with E. necatrix, mature schizonts were harbored in the lamina propria close to the muscularis mucosae of the small intestine and caused a severe hemorrhage in the host tissue. At that time contractility was reduced remarkably in the anterior part and mildly in the other parts of the small intestine. E. necatrix infection exerted a prolonged effect on the contractility of the small intestine and cecum on the 10th day postinfection, though the severe symptom had already disappeared from the host. In the severe symptomatic period of Eimeria infection, acetylcholine induced contractilities of the anterior and posterior parts of the small intestine were studied. These contractilities were different between E. tenella or E. acervulina infection and E. maxima or E. necatrix infection. This difference may have been due to the difference in the response of the anterior part of the small intestine to the histological damage caused by the parasite among the four species of Eimeria.

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In sixteen adult mongrel dogs, cardiac arrest was induced experimentally by administration with digitalis or acetylcholine, electroshock of the right atrium, hyper- or hypothermia, or asphyxia. Resuscitation was carried out just before and/or after cardiac arrest. Electrocardiograms were recorded with A-B lead in each experiment and analyzed. From the results obtained from the present experiments, it was presumed that cardiac arrest might be classified into two categories, reversible and irreversible. It was very difficult to bring to life animals in which there was a shift from extrasystole to flutter or fibrillation, or in which fibrillation suddenly appeared. As the mechanism of heterotopic stimulus formation in these animals, it was assumed that the exciting level of the secondary pacemaker might be higher than that of the primary one. On the contrary, it was not impossible to resuscitate dogs in which sinus bradycardia progressed or shifted to atrio-ventricular block. These arrhythmias were caused mainly by disturbances in excitatory conduction. Although the arrhythmias caused by the heterotopic ritimulus formation were observed in several dogs of the second category. As the mechanism for their occurrence, it was assumed that the exciting level of the primary pacemaker was disturbed to an abnormal extent.

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In the previous paper of this series, the body movement of the carp was studied from a mechanical point of view by the use of the electromyographical technique. In the present paper investigation was carried out on the mechanism of the pectoral fin movement and the function of the pectoral fins in the swimming movement. A carp was restrained to a fish-holder in the water-tank. Certain reflex movements of the pectoral fins were evoked by tactile stimulations given to some selected parts of the carp. They apparently resembled the movements in free swimming. The pectoral fins were observed by detailed anatomical dissection. The reflex movements were analyzed by cinematography and the activities of the muscles of the pectoralfins by electromyography. The results obtained are summarized as follows. 1) There were five muscles concerned with the movement of the pectoral fin in the carp. 2) The movements of the pectoral fins were essentially divided into four patterns: forward flexion, backward elevation, downward flexion and horizontal opening. 3) The pectoral fins displayed fundamental functions essentially in the case of swimming backwards, rising or going down, turning to the right or the left, and keeping a bodily balance in the water.

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The purpose of this study is to investigate the migratory behavior of Metastronglylus apri larvae artificially attenuated by X-ray irradiation. Guinea pigs were inoculated orally with 2, 000 M. apri larvae irradiated with 5×10⁴R of X-rays and killed at various intervals after inoculation. Various tissues were collected from them and examined for larvae by the pepsin digestion method (group A) and additionally by the microscopical method (group B). All larvae recovered were examined for the number and developmental stage. The results obtained were compared with those from normal larvae [4]. They are summarized as follows. On the 1st to 3rd days after inoculation, a large number of 3rd- or 4th-stage larvae were recovered from various tissues, as well as from the same tissues of normal controls. From the lungs, a few female 5th-stage worms were recovered on the 5th to 12th days, but no worms on the 15th day or later. There were no larvae in the thoracic cavity, blood from the right heart, or small intestine on any given day. In the tissues, especially in the walls of the cecum and the anterior part of the colon, and on the omentum, many larvae grew to early 4th-stage ones, but few to advanced 4th-stage ones. All the worms recovered from the lungs grew to early 5th-stage ones, but failed to reach the mature state. On the basis of these findings, it is concluded that 5×10⁴R X-irradiated larvae could penetrate rapidly into the gut and migrated for about 1 to 3 days after inoculation like normal larvae, but that they could grow neither to advanced 4th-stage ones nor to early 5th-stage ones. In other words, it can be seen that 5×10⁴R X-irradiation affected M. apri larvae over, or at least immdiately after, the period of transition from the 4th to 5th stage. The 4th stage, however, was sustained longer in the X-irradiated larvae than in normal ones. All the larvae that had invaded tissues may have been caught mainly in the gut, on the omentum, or at other sites to be killed and organized in these tissues.

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