Fig. 32. Tendon of finger at different ages, magnified 215 diameters, showing relative proportion of oval masses of germinal matter and formed material. a.-Child at birth.

b.-Old man, aged 74.

Fig. 33. Tendon from the finger of a child at birth. The preparation has been altered by teasing and pressure. Prolongations from the germinal matter are seen at various points giving the masses a stellate appearance. These prolongations are seen to terminate in the tissue of the tendon. On a level with a in the central part of the figure the arrangement is represented.

PLATE VI.

To illustrate the structure of certain forms of fibrous tissue.

Fig. 34. Tendon from finger of an old man age 74 showing different appearances produced in the oval masses of germinal matter (nuclei) by stretching in different directions. a.-Appearance of prolongation of germinal matter stretched longitudinally (nuclear fibre) under a power of 1700 diameters. b.-Appearance of fine fibre of yellow elastic tissue under the same power. c.-Fibre stretched in a longitudinal direction. d.Appearance generally observed in unstretched tendon. Fibre slightly stretched laterally. f.-Appearance produced when the fibre was stretched laterally and subjected to

pressure.

e.

Fig. 35. Development of bundles of fibrous tissue connected with the subcutaneous areolar tissue of the frog. a.-At an early period. b.-When the bundle of fibres has been formed. The nuclei are seen to be separated by a considerable distance, but are connected together with a certain proportion of imperfectly formed tissue which is soft and still granular. This is represented in the drawing rather wider than it is in nature.

Fig. 36. Thick false membrane found between the liver and diaphragm. a.-A thin section under a power of 215. b.-An

beca

n-kory young cartilage o me alrator separet d by a endị lyf meed in servering substance. .t nattlich exlali's G1 5, coleurdy carwine, and a oloured. The ca er portion is grai into matrix. -An elementa The ontermost ens *; next come layers of germinal 1oing to vers on into cartilage, : 4e nuch ui.. the centre of the mass. d.-ler, sementar: seting of illy-formed cartilage, yped cart taga, germinal master and the nucleus. that not ones the germinal matter undergo fors tils re at its external surface but that this 108 r as well the central part. f, g-Show

har.

f

h

Fig. 41.

b

Fig. 42.

b

O

April, 1861.

the same change in a still greater degree. h.-Marks the position originally occupied by the germinal matter of cartilage, but this substance has entirely undergone conversion into matrix. The nucleus is dead and is therefore no longer coloured with carmine.

Fig. 41. Is a thin section through the temporary cartilage of the os calcis with the periosteum and tendon inserted into it. a.-Is the cartilage. The masses of germinal matter result from division, and some are seen actually undergoing the process, but in all cases the resulting masses are at once separated from each other. b.-Corresponds to the periosteum. Here stellate masses of germinal matter are observed, the processes of which are continuous. These also result from the division of masses of germinal matter but unlike those of cartilage, the resulting masses remain for some time continuous with each other. c.-Marks the tendon in which the masses of germinal matter are continuous but arranged linearly and not in the form of stellate masses as in the periosteum. a. near the centre of the figure marks a capillary vessel.

Fig. 42. Shows the structure and mode of development of cartilage in the mouse, and illustrates the manner in which fatty matter is deposited in the 'cells.' From the ensiform appendix of a young white mouse. The figures a, b, c, very much resemble those in the upper figure. d.-Germinal matter and nucleus with a small oil globule deposited in the germinal matter. e. The same, but the oil globule has increased in size. f.-A further stage of the same change. The germinal matter and the nucleus are now seen lying between the globule of fatty matter and the formed material (wall of the cartilage cell). This is the position corresponding to that which the nucleus occupies in the fat vesicle and the primordial utricle in the starch-cell.'