Hydra, enlarged approximately 30 times, in SOMSO-PLAST®. After Christian Groß, Director of Studies. The anatomy of the hydra is shown in longitudinal section: entoderm, mesoglea, ectoderm, male and female gametes, buds and mouth opening. A detailed block of the wall of the body in the region of stomach and intestine, enlarged approximately 200 times, clearly shows the microscopic structure in cross and longitudinal section, and especially the structure of the various types of cell (cnidoblasts, muscle cells, phagocytes, adenocytes, replacement cells, and the nerve network). In one piece. On a green base.