140 - FORCED MOVEMENTS. 



50. Geotaxis changed in sense according to the external conditions in the case of 

 Paramoecium, 



51. Chemotaxis. 



(a) Flagellates moving into regions of optimum concentration of dissolved oxygen. 



(6) A collection of leucocytes seen inside the mouth of a capillary tube containing 



starch, which was introduced on the previous day beneath the skin of a toad. 



