82 The Ottawa Naturalist. 



and extend even into the funnel-shaped mouth. Noctiluca is a good 

 example of a flagellate creature. Paramcecium is a type of a ciliated 

 animalcule. In the latter the cilia serve not only to drive the creature 

 about, they carry food into its mouth. They perform this latter lunction 

 also in the bell shaped Votticella, and in Sientor, the trumpet animalcule. 

 These microscopic animals are rooted by a stalk, and the circle of cilia, 

 around the mouth-opening, sweeps in floating particles of food. When 

 Vorticella becomes detached the cilia, at once, carry it swiftly about 

 from point to point. Cilia, again, are chiefly food-carriers in those 

 lowly animal forms, the sponges. The substance of a sponge is 

 traversed by channels provided with waving cilia. While carrying in 

 food and aiding nutrition the cilia assist in respiration by maintaining 

 a constant circulation of water. Nutrition and respiration are also 

 accomplished in aquatic mollusca by means of cilia. The river mussels, 

 for example, inhale constant streams of water. These streams are pro- 

 duced by the countless cilia, with which the gills are covered. If a 

 fragment of a gill be torn off the cilia immediately carry it through the 

 water most vigorously. The intestine in these molluscs, is also ciliated, 

 and in the pond snails the tentacles and various parts of the body are 

 richly so. Again, among the zoophytes cilia though present are cf 

 inferior importance. They stud the crown of tentacles and line the 



stive tract, just as they do in certain worms, notably the tube- 

 building species. In such marine annelids as Terebella, the gills, cirri, 

 and tentacles, which form a crown around the head of the animal, are 

 ciliated and it has been observed that, when the tube is being built. 

 particles of sand and mud are driven along the tentacles to the pro 

 trusible proboscis by means of these cilia. The branchial cilia aid in 

 respiration. 



While some worms are non-ciliated, others are so abundantly 

 clothed with them, that the surface of the body exhibits a constant 

 shimmering appearance. Certain ciliated pate lies subserve sensory 

 functions, such as smell, etc., but the excretory or " segmental "organs, 

 i h.uai teristic of the Vermes, always possess a ciliated canal for ensuring 

 the outflow of waste products. The digestive tube also in these 

 creatures is observed to be lined with cilia in most cases. 



