ORIGIN AND FUNCTION OF THE LYMPH. 527 



elusion that nearly, if not quite all, of the lymph-corpuscles 

 are developed by genesis in the clear lymph-plasma, and that 

 their development goes on as the fluid circulates toward the 

 venous system. With regard to the influence of the lym- 

 phatic glands upon the generation of leucocytes, there is no 

 evidence that the corpuscles which are developed in the 

 course of the lymph through these organs are not here, as 

 elsewhere, formed simply from the blastema ; and it is not 

 necessary to invoke any special formative action taking place 

 in the peculiar structures of the glands. 



The function of the lymph-corpuscles is obscure. They 

 are discharged into the blood, of which they form a constant 

 constituent. Aside from the hypothesis that they are con- 

 cerned in the formation of the red blood-disks, no definite 

 and reasonable theory of their physiological office has been 

 proposed. 



In addition to the ordinary leucocytes and a certain num- 

 ber of fatty granules, a few small clear globules or granules, 

 about T jVo- of an inch in diameter, called sometimes globu- 

 lins, are almost constantly present in the lymph. These are 

 insoluble in ether and acetic acid, but are dissolved by am- 

 monia. They are regarded by Robin as a variety of leuco- 

 cytes and are described by him as free nuclei. They make 

 their appearance in the blastema before the larger leucocytes 

 are developed. 



Origin and Function of the Lymph. There can hardly 

 be any doubt concerning the source of most of the liquid 

 portions of the lymph, for they can be derived only from the 

 blood. Although the exact relations between the smallest 

 lymphatics and the blood-vessels have not been made out in 

 all parts of the system, there is manifestly no anatomical 

 reason why the water, mixed with albumen and fibrin and 

 holding salts in solution, should not pass from the blood into 

 the lymphatics ; and this is rendered nearly certain if it 

 can be demonstrated that the lymphatics partly or entirely 



