TISSUES IN GENERAL. 



117 



To these observations in cartilage I add a series of researches 

 in different other tissues of the body. 



Medullary tissue. The medulla between the trabeculae of a 

 shaft-bone of a newly born pup consists of lumps of protoplasm, 

 which are imbedded in a homogeneous basis- substance. These 

 lumps vary greatly in their aspect. However the corpuscle may 

 look, invariably spokes emanate from it which pierce the sur- 

 rounding light zone radiatingly, and are visible with high ampli- 

 fication only. Where the lumps are near each other, the spokes 

 directly connect them; if, on the contrary, the lumps are 

 separated from each other by broad layers of basis-substance, the 

 spokes of a lump enter the latter, and in most instances disap- 

 pear. (See Fig. 33.) 



The elements of the medulla termed u osteoblasts n by Gegen- 

 baur* exhibit the same features both in the medullary spaces of 



FIG. 32. CARTILAGE CORPUSCLES FROM THE CONDYLE OF FEMUR OF A 

 NEW-BORN PUP. [PUBLISHED IN 1873.] 



Chromic acid specimen slightly stained with chloride of gold. C 1 , corpuscle with one 

 compact, vacuoled nucleus ; C*, with a pale heap of granules above it ; Cs, with two nuclei and 

 several heaps of granules. Magnified 1000 diameters. 



newly born pups, close to the bony trabeculae, and in the vascular 

 canals of shaft-bones of older animals. 



Where the elements lie close to the bone- wall, they are sepa- 

 rated from the latter by a light rim, and the filaments, springing 



* Jenaische Zeitschr. f. Mediz. und Naturwissensch. I. Band. 1864. This 

 observer knew already delicate offshoots, like cilia, emanating from osteo- 

 blasts. 



