LYMPHOID ORGANS. 1 23 



we think that milliards of lymphoid cells are here surrounded 

 by perforated surfaces. 



When our organ becomes enlarged in its pulp, the contact 

 surfaces between the blood current and the lymphoid tissue 

 increase materially. The latter now sends off more con- 

 siderable quantities of its cells into the former. The number 

 of the colorless blood corpuscles is thus necessarily increased. 

 This is the lienal leucaemia, as it is called by the doctors, a 

 disturbance of the equilibrium between the blood and spleen 

 tissue, with the saddest consequences. 



Lymphatic passages occur with certainty in the capsular 

 and trabecular systems of the spleen. As to what is thought 

 to have been met with in the true lymphoid tissue, it stands 

 on a weak foundation. 



In the embarrassment of our knowledge we here include 

 several parts of the body which a former epoch has, like the 

 lymphoid organs described, also called "glands," and for 

 which their successors found the likewise very unsatisfactory 

 name of the "blood-vascular glands." 



We speak of the thyroid gland, the suprarenal capsule and 

 the apophysis cerebri, structures which to the present time 

 mock all physiological explanation, and once more confirm 

 the old saying, that even the trees do not grow up into 

 heaven. 



The thyroid gland, the glandula thyroidea of the anatomist, 

 lies, as is known, in front of the respiratory passage leading 

 to the lungs. Every one in the Canton of Zurich knows 

 that it forms the goitre, that national decoration. We physi- 

 ologists are, unfortunately, scarcely able to say more con- 

 cerning it than the people. 



Let us, then, examine the strange organ somewhat more 

 closely. 



In a connective tissue frame-work we meet, closely ap- 

 proached to each other, rounded, oblong or even more irreg- 

 ular cavities of 0.05 to o. 1 mm. The inner wall is beset 

 with a single layer of low cylindrical cells, 0. 02 mm. high and 

 O.oi wide. The cavity is filled at an early period with a 



