276 



SPECIAL HISTOLOGY. 



described, and are placed so close together, that, according to Harting 

 (1. c., p. 78), from 709 to 1120, or, on the average, 910 of them 

 occur within the space of a square millimeter. They lie for the 

 most part within the lamellae, but also between them, and are in- 

 variably placed with their broad sides parallel with the surfaces of 

 the lamellae. The canaliculi proceeding from them are much branched, 

 and penetrate the osseous substance in all directions, their course 

 being irregular, and often actually curved. They proceed prin- 

 cipally, however, in the first place, from both surfaces of the lacunae 

 straight through the lamellae ; and secondly, parallel with the Ha- 

 versian canals, from the two poles of the lacunae. It is only in 

 certain limited spots that these canaliculi present ccecal termina- 



Fig. 115. 



Fig. 116. 



tions ; everywhere else some of them anastomose in the most various 

 ways with the canaliculi of the neighboring lacunae, whilst others 



FIG. 115. From a transverse section of the shaft of the humerus; magnified 300 diam.: 

 a, Haversian canals; 6, lacunae with their canals, in the Haversian lamellae; c, lacunae of 

 the interstitial lamellae ; d, lacunae with unilateral canaliculi proceeding to the surface of 

 the Haversian system. 



FIG. 116. Section parallel with the surface from the shaft of a human femur ; magnified 

 100 diam. : a, vascular canals: 6, lacunae seen from the side, belonging to the lamella of 

 these canals ; c, lacunae viewed on the flat side, in lamellae which are cut horizontally. 



