800 OP THE STRUCTURE AND FUNCTIONS OF MUSCULAR TISSUE. 



the corpuscles of lymph ( 154) and pus ( 377), by the salivary corpuscles 

 ( 102), and connective tissue ( 40), and by pigment 1 ( 39), and cartilage- 

 cells, as well as the rhythmical protoplasmic movements observed in the eggs 

 of osseous fishes, 2 represent, perhaps, the simplest modes in which this power 

 is displayed. The movements presented by the greater number of these 

 cells, or corpuscles resemble those performed by the germinal mass of which 

 an Amoeba is composed, the form altering from round to oval or guitar-shaped, 

 and processes being thrust out at various points into which the body of the 

 corpuscle is again drawn, by which a veritable locomotion is effected. The 

 movements occurring in the fission and cleavage of cells appear to belong 

 to the same category. In all these instances the motions are usually slow 

 and interrupted, but are rendered more energetic and lively by warmth and 

 electricity, and are retarded by cold. In Dr. Ransom's experiments, the 

 presence of oxygen in the surrounding medium was found to be requisite for 

 the exercise of the property of the rhythmic contractility possessed by the 

 food yolk, as well as of the fissile contractility of the formative yolk, whilst, 

 on the other hand, the presence of carbonic acid rapidly checked, or alto- 

 gether arrested them. 3 The several movements here alluded to appear to be 

 of the same kind as those observed in the contraction of muscle, only that 

 the power is generally diffused through the whole of the cell or mass of ger- 

 minal matter, instead of being limited to an organ of definite structure ; just 

 as in some of the lower animals the power of perceiving light seems to be 

 diffused through the body, when no distinct organ of vision has as yet been 

 developed. 



655. A second kind of movement is presented by the cells of ciliated 

 epithelium ( 39), which line parts of the respiratory and genito-urinary ap- 

 paratus in man, and in him appear to have as their office the establishment 

 of currents directed' to wards the exterior of the body in the fluids covering 

 the surface of these membranes; whilst in animals they frequently constitute 

 important agents in effecting locomotion, and in the procurement of food. 

 The vibrations, which are upwards of 700 per minute, 4 do not appear to be 

 in any way under the control of the nervous system, since they persist long 

 after somatic death. When they have become languid they can be made to 

 recur with vigor for a short time by the addition of a small quantity of a 

 dilute solution of potash or acetic acid. Carbonic acid gas soon arrests the 

 movements, but the admission of oxygen gas leads to their renewal, and 

 this alternate action may be kept up for two or three times ; when they 

 have stopped they can also be renewed by the attion of induced currents of 

 electricity. The vibratile motions presented by the spermatozoa appear to 

 be of the same nature as those of ciliated epithelium, and each zooid may 

 be regarded as a cell, provided with a single cilium. Neither in these cells 

 nor in the corpuscles mentioned in the foregoing section are any morpho- 

 logical characters discernible. 6 



1 The pigment-cells in the skin of the frog appear, from the experiments of Mr. 

 Lister, Phil. Trans., 1858, to bo in some measure under the influence of the nervous 

 system, and the black particles in them when set free by the rupture of tho cell, ex- 

 hibit remarkable quivering movements, termed Brunonian movements. 



' W. H. Ransom, M.D., Humphry and Turner's Journ. of Anat. and Phvsiol., 

 vol. i, p. 237. 



3 SIT also Rossbach, Die rhythm. Bewegung-orschein. der einfaehsten Organism 

 und ilir Wrlmlten <;egen physikal. agent, und Arzneimittel, in Vorhand. d. Phvs.- 

 Med. Gesollsch. in Wurzburg, Bd. ii,"p. 179; Abst. Centralblatt, 1872, p. 490. 



1 Kngelmann, Centralblatt, 1867, No. 42. 



s See Kiilme, Sehult/.e's Archiv, Bd. ii, 1867, p. 372, and Klein, in Sanderson's 

 Physiological Handbook, 1873, p. 21. 



6 Unless indeed the striae described by Dr. A. Stuart (Zeits. f. rat. Med., Bd. xxx, 



