40 COLLOID DEGEXERATIOy. 



do these spheres originate? How are they derived from pre- 

 existing cells ? AVe may answer this question 

 in two ways. The protoplasm of the cell may 

 assume throuo-hout a uniformly homogeneous 



O I/O 



and more highly-refractive character ; the 

 cell, as a whole, being gradually transformed 

 into a colloid s})here, in the interior of 

 which, by the addition of appropriate re- 

 agents, we are able, for a time at least, to 

 demonstrate the central nucleus. Or the col- 

 loid sphere may originate at one point in the 



^ ,, , . protoplasm, near the nucleus, or, accordinir 



Ceils undergoing ^ ^ ' . /- i i 



colloid degene- to some authors, m the place of the nucleus. 



ration. From a Small at first, it grows to a size so consider- 

 able that the residual portion of the cell is 

 pushed aside, becoming, as it were, a mere appendage of the 

 sphere. At this stage the cell tends to assume the form of a 

 ring surrounding the sphere ; of a signet ring when the still 

 existing nucleus forms a projecting knob at one point in its cir- 

 cumference (cf. fig. 12). 



Finally, the colloid sphere escapes from its place of origin, 

 leaving the remainder of the cell behind as a granular mass, 

 which speedily crumbles away and disappears. 



The colloid spheres, whatever their origin, continue for a 

 time to grow, i.e. to swell (for they become less and less distinct 

 in the process), until their refractive index equals that of the 

 colloid mass already present, with which they may be said to 

 blend in the strictest sense of the word. 



As colloid matter, like mucus, is capable of swelling greatly 

 by imbibition, the colloid metamorphosis becomes proportionately 

 conspicuous to the naked eye. Little groups of from ten to 

 twelve cells, which, before their metamorphosis, can hardly be 

 said to exist for the unaided eye, are converted into a jelly-like 

 particle, still very small, but quite visible, as we have already 

 pointed out with reference to the cell groups of the nucleus gela- 

 tlnosus after they have undergone colloid degeneration (§ 41). 

 The greater the size of the particle the more marked is its 

 amber tint, its transparency, and its tremulous, jell}— like quality. 

 But these properties only last until the particle reaches a certain 

 size, or, to speak more accurately, a certain stage of develop- 



