402 THE KETIFORM TISSUE OF THE INTESTINE. [BOOK II. 



In lymphatic glands, as well as in the mucous membrane of the 

 intestine, the meshes of reticular tissue contain cells which closely 

 resemble the colourless cells of the blood and of the lymph. These 

 are denominated lymphoid cells and the term adenoid or lymphoid 

 connective tissue is applied to the retiform or reticular tissue in the 

 above situations. 



Mali's re- I n the course of his researches on the structure of 



reticular or retiform tissue, F. P. Mall was led to the 

 conclusion, lately abundantly justified, that the fibres are not 

 identical in chemical composition with the white fibres of areolar 

 tissue. He was at first inclined 1 to look upon them as composed of 

 a substance closely resembling elastin, though he subsequently 

 arrived at the correct conclusion that the substance is neither 

 identical with that of white nor of yellow elastic fibres 2 . F. Mall 

 having subjected reticular tissue to the action of boiling water for 

 long periods, found that the aqueous extracts did not gelatinise. 

 He discovered, however, the fact that reticular tissue is not affected 

 by long digestion with trypsin. 



R. A. Young's Under the direction of Professor Halliburton, Young 

 researches. re-investigated the question as to whether reticular 

 tissue is identical with, or differs from, white fibrous tissue. He 

 shewed that Mall had been led into error in supposing that when 

 reticular tissue is boiled, no gelatin is formed, but he unfortunately 

 allowed himself to arrive at a conclusion which was not warranted 

 by the facts discovered and which tended to obscure the perfectly 

 correct opinion which Mall had formed as to the individuality of 

 reticular tissue. 



Young summarised his researches as follows: "The general 

 outcome of this research is that retiform tissue as contained in the 

 alimentary mucous membrane and lymphatic glands yields a small 

 amount of gelatin, which is however capable of being estimated 

 quantitatively. There are therefore no grounds for supposing with 

 Mall that the fibres which compose the r6ticulum are different from 

 the white fibres in other connective tissues. Microscopically they 

 have the same characteristics, and the present research shows that 

 they are also the same in chemical composition 3 ." 

 Siegfried's J n a dissertation published at the close of the year 



1892 4 , Siegfried shewed that the purified reticular 

 tissue of the intestine is, as Mall had supposed, entirely distinct in 

 chemical composition from white fibrous tissue. When boiled in 



1 F. P. Mall, 'Die Blut- und Lymphwege im Diinndarm des Hundes,' Abhandl. d. 

 math.-phys. Cl. d. konigl. sticks. Ges. d. Wiss. Vol. xiv. (1887), No. m. 



2 F. P. Mall, ' Das reticulirte Gewebe,' Ibid. Vol. xvn. (1891), No. xiv. 



3 K. A. Young, B.Sc., 'The Fibres of Ketiform Tissue,' (from the Physiological 

 Laboratory, King's College, London), Journal of Physiology, Vol. xm. (1892), pp. 332 

 334. 



4 Dr Max Siegfried, 'Ueber die chemischen Eigenschaften des reticulirten Ge- 

 webes' (Habilitationsschrift, &c.), Leipzig, Dec. 1892. 



