GENEKAL CHAKACTERS OF CONNECTIVE TISSUE CELLS. 53 



several forms. Amongst the microscopic morphological consti- 

 tuents thus distinguishable in connective tissue may be enume- 

 rated cells; networks and trabeculse, developed from cells 

 consisting of peculiar delicate unbranched fibres (connective 

 tissue fibrils), for the most united into fasciculi ; and, lastly, 

 fibres which are differentiated from those above named by the 

 resistance they offer to the action of acetic acid and alkalies, 

 by their repeated division, by their forming networks, and by 

 their fusing into lamellae (elastic fibres). 



OF THE CELLS OF CONNECTIVE TISSUE IN GENERAL. 



In all connective tissues, whether obtained from an adult 

 organism or from one in process of development, cells may be 

 found, the number of which in different instances varies within 

 ery wide limits. In the cells obtained from connective tissue 

 we observe so many different conditions of activity, develop- 

 ment, metamorphosis, and disintegration, and know so little 

 respecting their material composition and changes, their phy- 

 siological peculiarities, and their genetic connection, that it is 

 impossible to give a general description, which shall be appli- 

 cable to all the forms they present. On the other hand, a few 

 facts may be here stated which are of general importance in 

 regard to the cells contained in connective tissue, and will thus 

 enable us to take a broad view of the subject ; and, in the first 

 instance, the researches commenced by Von Recklinghausen * 

 and Kiihne t on the living tissue may be adduced. 



In the living body the cells of connective tissue may be ob- 

 served wherever it is possible to make thin sections adapted for 

 high magnifying powers quickly, and without the employment 

 of any hardening process. They may then be subjected to 

 microscopic investigation, after the addition of some indifferent 

 fluid, as serum, the aqueous humour, and serum containing 

 iodine, especially with the aid of a moist chamber. In speci- 

 mens so prepared, Von Recklinghausen first observed the pre- 



* Loc. cit. 



t Untersucliungen uber das Protoplasma und die Contractilitat, p. 109. 

 Leipzig, 1864. 



