CONNECTIVE TISSUE. 221 



neglected. The best specimens are obtained from portions in 

 which the basis-substance is not entirely decalcified, as in these 

 the bone-corpuscles arid their offshoots, as well as the corre- 

 sponding cavities in the basis-substance, the lacunae and canal- 

 iculi, are best preserved. For mounting, only dilute glycerine 

 should be used. ' 



A number of examiners have attempted to settle the question 

 whether the lime-salts are deposited mechanically in the basis- 

 substance, or whether there is a chemical union of the molecules 

 of lime and glue. The question probably will never be satisfac- 

 torily answered. This much is certain, that by the extraction of 

 the lime-salts by means of chromic acid, no material changes are 

 produced in the glue-yielding basis-substance. 



Bone-corpuscles. As early as in 1850, E. Virchow discovered 

 the identity of the "bone-cells" with other " connective-tissue 

 cells. 77 Though he at first held the mistaken idea that the walls 

 of the cavities were the bone-cells proper, he admitted later 

 that the cavities, being hollow and filled with a liquid, hold 

 the bone-cells. He was the first who recognized them to be 

 the seats of life, and able to proliferate and produce medullary 

 tissue. 



As late as 1871, Ed. Lang, in Strieker's laboratory, recog- 

 nized the bone-corpuscles to be living matter or protoplasm in 

 the fresh condition, endowed with the property of amoeboid 

 change. In this view the bone-tissue, as well as every other 

 variety of connective tissue, is built up by a calcified, glue- 

 yielding basis-substance, containing scattered cavities and outlets 

 of the cavities the lacuna? and canaliculi of former histologists ; 

 the lacunas are filled with living matter, the bone-cells or bone- 

 corpuscles. Nothing positive was known at that time as to the 

 contents of the canaliculi. 



In 1872,* I undertook to study bone-tissue, both in fresh 

 and preserved specimens. In fresh sections, taken from the con- 

 dyle of the femur of young rabbits, transferred to the slide 

 together with a drop of a one-half per cent, solution of table-salt, 

 or, still better, of Muller's liquid, with an immersion lens No. 10 

 of Hartnack, I recognized the bone-corpuscles. They were round 

 or oblong bodies of a grayish tint, lying in a shining basis- 

 substance, which appeared traversed by numerous light canals. 



* " Studien am Knoehen und Knorpel." Wiener Mediz. Jahrbiicher, 

 1872. 



