LIVING CONNECTIVE TISSUE CELLS 141 



can scarcely avoid the interpretation that the cells shown in fig. 

 10 were at the moment of 'fixation' moving along the surface of 

 the fiber bundles against which they lie. 



The pronounced morphological relation between the connective 

 tissue cells and fibers cannot but have an equally close functional 

 relation. What those functional relations may be we are not 

 now possessed of the data to fully determine. 



Further studies will be necessary to fully understand the part 

 played by the active moving connective tissue cells in the pro- 

 duction and growth of the collaginous fibers. So far as they are 

 now determined the essential phases of the process in which the 

 connective tissue cells are concerned appear to be: (1) the connec- 

 tive tissue arises from a primitive mass of round mesenchymal 

 cells; (2) there is a change of form from round to stellate, to 

 spindle, and eventually to lamellar cells; (3) certain fibers seem 

 first to appear within the cells, possibly at their surface (Hansen, 

 Golowinski) ; (4) there is formed a reticulum pervading the inter- 

 cellular ground substance whose fibers may be, though they not 

 necessarily are, identical with those first arising within the cell; 

 (5) coincident with the origin of fibers there begin amoeboid move- 

 ments in the stellate and spindle cells; (6) there is an increase in 

 size and number of fibers in the reticulum and they aggregate 

 into bundles, synchronously with which first the stellate and later 

 the spindle cells move along the surface of the fiber and fiber 

 bundles. 



In conclusion I desire to express my sincere thanks to the 

 Marine Biological Laboratory at Woods Hole, Massachusetts, 

 for the opportunities so kindly placed at my disposal. 



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Aknold 1893 Arch. f. path. Anat., vol. 132, p. 502. 



Boll, Franz 1872 Arch. f. mikr. Anat., vol. 8, p. 28 



Burrows, M. T. 1911 Jour. Exp. Zool., vol. 10, p. 63. 



( ' arrel, Alexis, and Burrows, M. T. 1910 Jour. Am. Med. Assoc, vol. 55, 1379. 



1911 Jour. Expr. Med., vol. 13, p. 416. 

 Ferguson, J. S. 1911 Am. Jour. Anat., vol. 12, p. 277. 



1911 Biol. Bull. vol. 21, p. 272. 



