64 HISTOLOGY 



Connective tissue fibrils are produced from the chondrioconta which come to lie at 

 the surface of the cell. They then change their chemical constitution and are no longer 

 stained by iron haematoxylin or fuchsin. At this stage those which are in a row unite 

 end to end. Thus in the formation of a fibril numerous cells take part, each producing 

 a section. The fibrils again change their chemical constitution and become intensely 

 stained by the collagen stains. Finally they become free from the cells and lie in the 

 intercellular spaces. From the time of their first formation they have a wavy course, 

 which may become more marked later. This clearly means that the connective tissue 

 fibers have grown in length more than the surrounding elements. They increase also 

 in diameter through independent growth, and for a time new fibers are produced by the 



cells I differ with Flemming since I consider that connective tissue fibers 



are not formed within the cell body but are produced at the cell surface (by transformia 

 tion of the chondrioconta) ; I agree with him in deriving them from the cytoplasmc- 

 filaments. 



The umbilical cord has long been regarded as a particularly favorable 

 object for the study of white fibers, but the way in which they arise remains 

 undetermined. In addition to these white fibers, the umbilical cord con- 

 tains stiff fibers of a different nature, found at the periphery of the cells. 

 They are similar to the fibers of a tissue which forms the framework for 

 the branching nerve cells, thus binding them together, and accordingly 

 named neuroglia (v5pov, nerve, yXta, glue). Fibers similar to those 

 of the neuroglia, found at the periphery of muscle cells, are called border 

 fibrils or myoglia. In 1903 Mallory described similar border fibrils in 

 connective tissue and named them fibroglia. They are seen at the peri- 

 phery of the cells in the umbilical cord (Fig. 51, b). Mallory describes 

 them as follows (Journ. Med. Res., 1905, vol. 13, pp. 113-136) : 



Neuroglia, myoglia and fibroglia fibrils morphologically 'and in certain staining 

 reactions more or less closely resemble one another. They touch or form part of the 

 periphery of the cell protoplasm, but continue away from the cell in two directions, i.e., 

 they do not begin or end in the cell which produces them. How far the fibroglia are 

 accompanied by protoplasmic processes cannot be determined. The number of these 

 fibrils to a cell is not constant, but it is usually in the neighborhood of a dozen. 



Professor Mallory has found no transitions between the fibroglia and 

 the white fibers. Meves likewise considers them as entirely distinct, 

 and states that the production of white fibers by the cells of the umbilical 

 cord terminates by the fifth month. The fibroglia are present at birth, 

 and probably no tissue is more favorable for their study than the umbilical 

 cord at term. 



In addition to the mucous matrix, the white fibers, and the fibroglia, 

 mucous tissue contains cells and intercellular spaces. The cells, at first 

 stellate with many anastomoses, become elongated and more or less dis- 

 connected from one another. Three of their nuclei are shown in Fig. 51, 

 but their cytoplasm forms a thin layer, the limits of which can scarcely 

 be determined. The intercellular spaces contain a fluid through which 



