Dr. Holló Ferenc - Dr. Murai Éva szerk.: Parasitologia Hungarica 5. (Budapest, 1972)
The muscular elements of the miracidium are situated under the subepithelium , and consist of concentric and longitudinal muscular fibres. The existence of muscular elements is indicated by the vital contraction of the miracidium, though only the longitudinal fibres were discernible by the applied microtechnical methods. No possibilities were provided to detect other details /number of muscular elements, presence of nuclei, etc/. The inner miracidial structure consists of the apical gland, the penetration glands, the nervous system, the excretory system and the germinal tissues /fig. 4/. The apical gland lies in the oral third of the body; fused from four cells,' its shape alters with the movements of the miracidium. The cells have no definite borders, but the nuclei are well discernible. The gland is situated along the longitudinal axis, its two outlets leading to the common aperture in the middle of the terebratorium / fig. 6 , T-^b/. The apical gland contains granular substance, moving freely together with the miracidium. The gland is supposed to play a role when penetrating the intermediate host. Laterally to the apical gland, two pairs of unicellular penetration glands are situated. The cells extend to the first and second epidermal rows, their round nuclei /6-7 /u/ appear basally. Their outlets are supposed to be the four large papillae /1.4-1.8 yu/ observable in the groups T-^a, c and T,-,a , b in the anterior view. The glands may be easily distinguished from the apical gland, since they contain no grains / fig. 9/ . The centre of the nervous system is the brain, situated dorsally in relation to the apical gland,a fibrous mass. Its shape may change according to the movements of the miracidium; during contraction it takes on a more or less rectangular form and during expansion a spiniform one. With the applied microtechnical methods, neither nerve cells nor nuclei could be detected, but in front of the fibrous mass there appeared certain cells
