CONNECTIVE TISSUES CELLS. 57 



the germ has been implanted in the mind of Man, and which, developed as 

 it is by the mental cultivation that is almost necessary for the formation of 

 the idea, has been regarded by philosophers in all ages as one of the chief 

 natural arguments for the immortality of the soul. By this immortal soul 

 Man is connected with that higher order of being, in which Intelligence 

 exists untrammelled by that corporeal mechanism through which it here 

 operates; and to this state a state of more intimate communion of mind 

 with mind, and of creatures with their Creator he is encouraged to aspire, 

 as the reward of his improvement of the talents here committed to his 

 charge. 



CHAPTER TIL 



ON THE MINUTE ANATOMY OF THE CONNECTIVE TISSUES. 

 CELLS AND THEIR DERIVATIVES. 



42. THE whole substance of the body in many of the lower forms of 

 Animal Life, and the elementary parts from which the several tissues are 

 formed in the higher, is composed of a soft gelatinous substance which was 

 named Sarcode by Dujardin, Protoplasm by v. Mohl and Remak, Cytoplasm 

 by Kolliker, Germinal matter by Beale, and in its various kinds represents 

 the " Physical Basis of Life," of Huxley. 1 It is transparent and homogeneous 

 and may be compared to white of egg. It usually presents a number of 

 minute granules distributed through its substance, which are derived in part 

 at least from the materials it has absorbed. It may exist in the form of 

 separate masses, varying in size from points scarcely perceptible with the 

 microscope, to such as are visible to the naked eye, or in the form of layers 

 or sheets lining the interior of cells and vessels. When at rest it is probable 

 that masses of protoplasm assume a spherical form, but under all ordinary 

 circumstances they are more or less flattened, and exhibit certain move- 

 ments, and present the phenomena of growth, nutrition, and reproduc- 

 tion. The movements witnessed in Protoplasm are of two kinds, both of 

 which are rendered conspicuous by the molecules in its substance. The first 

 is a vibratory, quivering, or dancing movement of the granules, resembling 

 closely those trembling movements of resinous and other inorganic particles 

 suspended in fluids, which, having been first described by Robert Brown, 

 are sometimes called Bruuoniau motions. Such vibratory movements are 

 chiefly seen in spherical masses of Protoplasm, and cease when these are 

 undergoing changes of form or place. The second kind of movement demon- 

 strates the contractility of protoplasm, which, as is shown by experiments on 

 the pigment cells of the Chameleon and various Amphibia and Fishes in 

 which the sarcode contains colored granules, is under the control of the 

 nervous system. The masses change their shape, .becoming elliptical or 

 ovoid, and flattened or irregular, owing to the thrusting out of processes, and 

 these may be either withdrawn or may drag the rest of the body after them, 

 so that a veritable change of place is effected. The processes may vary in 



1 The best account of Protoplasm is given by Kuhne in his essay entitled Das 

 Protoplasm, Leipzig, 18G4; but the reader may refer with advantage to the essay 

 on Cells by Strieker in his Manual of Histology, Syd. Soc. Translation, vol. i, p. 1, 

 where the chief authorities on this subject are cited ; to Huxley's lecture on The 

 Physical Basis of Life, in his Lay Sermons and Addresses; and to Haeckel's work 

 on General Morphology. 



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