138 JEREMIAH S. FERGUSON 



to the direction of visible fiber lines, yet a projecting process of 

 such a cell often appears to envelope or to become coincident with 

 a fiber. In the spindle cells locomotion is always so far as I have 

 observed, in the direction of the fiber lines: usually these cells 

 merely slide along the surface of fibers, blood-vessels and similar 

 structures. 



I have observed that the stellate cells are more prone to lie in 

 relation with the finer, the spindle cells with the coarser fibers; 

 the coarser fibers in most cases, because of their size, being pre- 

 sumably fiber bundles rather than single fibers. This relation- 

 ship is to be expected in as much as in stained preparations one 

 finds the stellate cells present with those finer fibers which repre- 

 sent the earlier stages in fiber formation. 



That fibers do lie without the cell in both embryonic and mature 

 connective tissue is generally conceded. That they lie within the 

 cell in reticular tissue, which in a way is comparable to an early 

 or embryonic type of connective tissue, I have recently demon- 

 trated by means of the Bielschowsky stain. 1 The types of fiber 

 development by fusion of intracellular granules described by 

 Spuler and by Lavini though perhaps not conclusively demon- 

 strated, at least show that certain granules which are in relation 

 with the first appearance of fibrils do lie within the substance of 

 the stellate, mesodermal, connective tissue cells. Moreover, I 

 have found in embryonic tissues (fig. 9) just such appearances as 

 I have described for reticular tissue. 2 By means of the Biel- 

 schowsky method such appearances can be shown throughout 

 embryonic connective tissue. I have observed them in pig- 

 embryos, of various ages, in the limb buds, the head, the cervical 

 region, and in the back throughout the whole length of the embryo 

 from the occiput to the caudal tip, also in the umbilical cord. In 

 many of these locations I have made similar observations on human 

 embryos of older stages but in which the connective tissue was 

 still actively developing. One is at a loss to explain the method 

 by which fibers arising within the cells arrive at a location out- 

 side the cell body when these cells are in active motion. The 



1 Am. Jour. Anat., vol. 13, page 277, 1911. 



2 Loc. cit., in which see especially fig. 4 and fig. 8, pages 285 and 289. 



