LTVING CONNECTIVE TISSUE CELLS 137 



and the contour of each cell at the point of contact remained clear 

 and distinct. Moreover it»would seem that since connective tis- 

 sue cells move extensively along the surfaces of the syncytium 

 that syncytium could scarcely arise by fusion of its cells. 



The spindle cells exhibit a certain stereotropism. They are 

 prone to take their position alongside a connective tissue fiber or 

 fiber bundle or against the surface of a blood-vessel or dermal 

 fin-ray. When in contact with a broad surface, such as that of a 

 blood-vessel or one of the lepidotrichia, the cells frequently assume 

 a flattened, lamellar form. This is shown by stained sections, in 

 which that type of cell predominates in these locations, and by the 

 observation of living spindle cells which frequently move up to 

 a blood-vessel or a fin-ray and then become so thinned out against 

 the surface that they finally vanish, being in the living tissue in- 

 distinguishable from the refraction lines which' surround the larger 

 bodies. Again, the spindle cells very frequently move up to a 

 connective tissue fiber or bundle and then elongate along the nar- 

 row filament until, as before, the cell finally appears to Vanish by 

 its extreme attenuation. Such a result was observed a moment 

 later than the recorded observation in the case of the cell shown in 

 fig. 51. 



It frequently happens that the spindle cells after such elongation 

 again thicken to a typical spindle form, and may even throw out 

 other processes, but in so doing, if the cell is observed in relation 

 to some relatively fixed point, e.g., a joint of a dermal fin-ray, a 

 chromatophore, or a blood-vessel, it will be seen that the cell has 

 changed its relative position; it has exhibited locomotion. Loco- 

 motion is not a distinguishing character of the spindle cell; it is 

 exhibited by the stellate cells, possibly also to a very limited 

 extent by those round cells which are only just beginning to pre- 

 sent pseudopod formation. But the character of the locomotion 

 in the several types of cells differs decidedly. In the stellate 

 type locomotion may take any direction and resembles a very 

 active amoeboid motion, processes being extended along the sur- 

 faces of fine fibers, then either retracted or increased in size until 

 the whole cell has come to occupy the place of the former process. 

 Though locomotion in the stellate cells is not entirely confined 



