370 



have not here a cell, m the sense in which that word was 

 understood some years ago. 



The nucleus is deeply coloured with carmine ; the pro- 

 toplasm is slightly coloured; the bundles of fibres become 

 transparent and appear only of a pale pink if the washing 

 after the action of the carmine has been sufficient. In the 

 thickness of the tendon there are no other cells but those of 

 which I speak. In accordance with this description, it is 

 clear that the tendons are traversed throughout their whole 

 length by tubes formed by the flat rectangular cells rolled up 

 and placed end to end. The two edges of a rolled up cell 

 which touch each other are soldered ; the two other edges are 

 similarly soldered to the corresponding edges of the cellules 

 placed above and below. This soldering is demonstrated by 

 the impregnation of silver ; when one of the little tendons is 

 placed in a solution of nitrate of silver of two parts to the 

 thousand, and is examined as soon as the impregnation is 

 produced, there is seen at the point of union of the tubular 

 cells, a dark line indicating that at this point there is an in- 

 termediate substance, as in epithelia (fig. 6, page 480). 

 The aspect of the cellular tvibes of the tendons vary accord- 

 ing to the age of the animals, the mode of preparation, and 

 according to the tendons submitted to examination. In 

 young mammalia, and during all the period of growth, the 

 tubular cells are very easily demonstrated in the tendons of 

 the tail, by employing the method Avhich I have indicated. 

 But in adult animals it is very difficult to obtain the opening 

 out of the tubular cells and their separation. This arises 

 from the fact that an amorphous, resistant and elastic mem- 

 brane is formed around the cells and throughoiit the whole 

 length of the tube. 



To render this elastic membrane very evident, it is neces- 

 sary to submit the tendons to a boiling process for five or six 

 hours. The connective bundles then become very transparent; 

 and a great number of fine elastic fibres are distinguished in 

 their place ; the sheaths of the tubes are very clean and filled 

 with granulations, the remains of cells swollen and destroyed 

 by the boiling. After a prolonged and powerful compression 

 made upon the filiform tendons from the tail of an adidt dog, 

 the little tendon may be exposed and even removed without 

 the elastic tubes being broken, and upon a similar prepara- 

 tion coloured with carmine one can discern only the red 

 stripes cut by transverse lines. With adult rodents it is 

 much easier to tear the elastic sheath. The tubular cells 

 open, and have the appearance of red plates, in which one 

 cannot at first discover the nucleus (fig. 3) . But when the 



