CILIA 



79 



CILIA 



of the retina suspended in fluid to fol- 

 low ciliary movement. The oviduct 

 or trachea of turtles or other reptiles 

 would be useful where it is not conven- 

 ient to control the temperature of tis- 

 sues from a warm blooded animal. The 

 ciliature of the avian and reptilian 

 oviducts has been described by Parker, 

 G. H. (Phil. Trans. Roy. Soc. B, 1931, 

 219, 381-419). Umeda, T. (Acta Der- 

 matologica, 1929, 6, 629-646) used ox 

 trachea which provides large ciliated 

 areas. He employed it to study the 

 effects of temperature, sugar solutions, 

 alkaloids, alcohol, x-ray, and ultra- 

 violet light radiation. The underlying 

 tracheal cartilage was removed with the 

 ciliated epithelium in pieces about 2 x 

 3 cm. and pinned out beneath a layer of 

 Ringer's solution at 38°C. It was fixed 

 at a slant of 10 to 15 degrees to facili- 

 tate the movements of millet seeds 

 placed on the surface. There is ob- 

 viously need for someone to recheck the 

 reactivity of the frog's pharyngeal cilia 

 against several other kinds of ciliated 

 epithelium and sort out the effects due 

 to the type of biological material used 

 from the real effects of chemicals or 

 other agents being tested. 



In the frog's pharynx and in the ten- 

 tacle of the snail (Merton, H., Pfluger's 

 Arch. Ges. Phys., 1923, 198, 1-28), 

 nerves are responsible for activation 

 of ciliary movement; whereas, in the 

 Ctenophore swimming plates (Gothlin, 

 G. Fr., J. Exp. Zool., 1920, 31, 403-441) 

 and the velar cilia of the nudibranch 

 veliger (Carter, G. S., Brit. J. E.xp. 

 Biol., 1926, 4, 1-26) the nerves are re- 

 sponsible for inhibition of ciliary ac- 

 tivity. The procedures used by these 

 authors are well adapted to differentiate 

 between inherent ciliary activity and 

 nerve regulation. In this same cate- 

 gory should be included the work of 

 Copeland, M. (Biol. Bull., 1922, 42, 

 132-142) who studied the r61e played 

 by nerves in regulating the ciliary ac- 

 tivity on the foot of the snail. 



Polarity and ciliary reversal have 

 been problems of considerable academic 

 interest. Coonfield, B. R. (Biol. Bull., 

 1936, 70, 460-471) described his opera- 

 tive techniques for reversing rows of 

 swimming plates in Ctenophores and 

 Twitty, V. C. (J. Exp. Zool., 1928, 50, 

 319-344) and later Luther, W., (Roux 

 Arch. Entw. Organ. 1934, 131, 532-539) 

 reported the relatively simple methods 

 used in reversing small segments of the 

 ciliated epidermis of the amphibian 

 larva. Induction effects on ciliary po- 

 larity have been worked out recently by 

 Twitty, V. C. and Bodenstein, D. (J. 

 Exp . Zool . , 1941 , 86, 343-379) . Reversal 



of tracheal epithelium in dogs was ac- 

 complished by Isayam, S. (Zeit. f. Biol., 

 1924, 82, 155-156) who found no reversal 

 of direction of ciliary beat. Ciliary 

 reversal is a well known reaction in 

 some ciliated protozoa, such as Para- 

 mecium and minimal techniques are 

 required for study of its physiology 

 (Oliphant, J. F., Physiol. Zool., 1942, 

 15, 443-452). Ciliary reversal in Meta- 

 zoa is rare indeed. Parker, G. H. (Am. 

 J. Physiol., 1905, 14, 1-6) employed 

 simple techniques to demonstrate its 

 existence in the labial cilia of sea- 

 anemones. Equally simple procedures 

 were followed by Matthews, S. (J. Exp. 

 Zool., 1928, 51, 209-262) to demonstrate 

 that the seeming reversal of the cilia- 

 ture of the pelecypod palp did not actu- 

 ally exist. Atkins, D., (J. Marine Biol. 

 A. United Kingdom, 1930, 16, 919-970) 

 observed permanent, natural reversal 

 in frontal cilia of the gill filaments of 

 Mytilus following injury. 



Numerous investigators have pre- 

 sented diagrams of the direction of cili- 

 ary movement in a field such as Irving, 

 L. (J. Exp. Zool., 1924, 41, 115-124) who 

 plotted the circulation of fluids and 

 particles within the coelom of the star- 

 fish. Another good example is the work 

 of Atkins, D. (Quart. J. Micr. Sci., 

 1936-1937, 79, 181-308, 339-373, 375-421) 

 who worked out carefully the direction 

 of ciliary movements in a great many 

 molluscs and evolved a phylogenetic 

 tree based, in part, on the lateral- 

 frontal cilia (Quart. J. Micr. Sci., 1938, 

 80, 345-436). Also the study made by 

 Meyer, A. (Biol. Zentralbl., 1936, 56, 

 532-548) on Nephthys hombergli illus- 

 trates a careful approach to this type 

 of problem. Barclay, A. B., Franklin, 

 K. J., and MacBeth, R. G. (J. Physiol., 

 1937, 90, 347-348) observed that mucus 

 is moved in a clockwise direction up 

 through the mammalian trachea. 

 Hilding, A. (Arch. Otolaryng., 1932, 

 15, 92-100) plotted the direction of cili- 

 ary movement in the human nose by 

 watching the direction of drainage of 

 the mucous sheet with a speculum after 

 dusting with face powder and observed 

 in the posterior two-thirds of the nose 

 a new mucous layer about every 10 

 minutes and about once an hour in the 

 anterior third. Lucas, A. M. (Am. J. 

 Anat., 1932, 50, 141-177) and Lucas, 

 A. M. and Douglas, L. C. (Arch. Oto- 

 laryng., 1934, 20, 518-541) used carbon 

 particles to plot the drainage pattern 

 for monkey, rat, mouse, rabbit, cat, 

 cow, and sheep. The potential error 

 resulting from following mucous flow 

 rather than direct observation of cilia 

 is shown on some wound experiments 



