258 



Dr. G. Thin. On Hyaline Cartilage. [Jan. 16, 



tions of it in different solutions, and then made sections which I stained 

 with various colouring agents. The sections thus prepared differed 

 from each other in a remarkable manner. 



Sections from a portion which had been placed for two days in 

 solution of bichromate of potash were stained by logwood, picro- 

 carminate of ammonia, and eosin respectively. In all of them the 

 ground substance of the tumour appeared as structureless, and through- 

 out it were interspersed a large number of rounded nuclei. In the 

 carmine-stained preparations many of the nuclei were immediately 

 surrounded by this homogeneous substance, without any appearances 

 of what might have been considered as cell-substance or as cell-pro- 

 cesses being observed. In some instances a scant, faintly granular 

 stained substance tapered for a very short distance from opposite poles 

 of the nucleus, producing the appearance of a spindle or fusiform cell. 

 More rarely a long slender stained projection tapered gradually from 

 one of the poles of the nucleus to a considerable distance, and seemed 

 to end in a fine colourless fibre. The appearances were such as have 

 been often described as indicative of cells with branching protoplasmic 

 processes. For example, some of these apparent cells resembled accu- 

 rately the smaller of the coloured figures described by Ranvier in the 

 omentum as " vaso -formative cells." 



The sections stained in eosin solution showed somewhat the same 

 appearances, although in a more exaggerated form. A homogeneous 

 unstained ground substance was permeated by process-like prolonga- 

 tions of a finely granular stained substance which surrounded the 

 nuclei, the prolongations from adjoining cellular centres anastomosing. 

 The distribution of these cell-like masses of stained matter was an 

 exact copy of the appearances seen in a cornea stained by gold chlo- 

 ride when what has been called the " positive image " is successfully 

 produced, and would certainly quite recently, if not now, have been 

 described by some histologists as a highly developed protoplasmic 

 network of branching cells (fig. 14). 



In the logwood sections the nuclei alone were stained, but stretching" 

 in various directions from the nucleus strong tapering colourless fibres 

 appeared to be given off. A system of branched cells, in which the 

 protoplasm was very scant, and the processes highly developed, was 

 exactly simulated. This appearance was the more deceptive, as when 

 the tissue was broken up with needles, numbers of these apparently 

 branched cells with broken processes were found free in the fluid 

 (fig. 13). 



Slices of the tumour had been placed fresh in solution of purpurine 

 ( Ranvier 's formula), and had been allowed to remain in it for several 

 days. The surfaces of the slices were well stained, but the colouring 

 action of the dye had not penetrated deeply. Thin sections were 

 made from the stained surfaces and examined in glycerine. The 



