I J Mill rOBMAI l' I IK' 1 19 



hut during activity tin- il<»u I mes mai I in not be explaii 



by filtration, bnl may !"• a tinted for by a physico 



namely, osmosis. The energy required for ti 

 cell is produced bj chemical <•! . whereby large mole* 



broken down into numerous small' i i smaller mol< 



then discharged int., the surrounding tis>uc fluids, the osmotic 

 of which they iner< with the consequence that 



a from the plasma in the blood capillarii i i 



increases the volume of ti>>n.- fluid, which is then drained 

 lymphatics I e increase in molar i tration will ale 



tissue juices, tending to make the '•••II Bwell up by absorhii 

 In gland cells this water is immediately extruded I 



water of the secretion (seepage J'_'l . 



An analogous method of lymph formation is not confined '<> situ 

 where the capillaries are relatively impermeable, for il 

 tin- liver, the lymph flow from which is greatly increased by the in 

 tion of hih' sabs ,\ similar process no doubt results from mu« 

 activity, although in this ease the tissue spaces must form a continn 



-in of their <>un, there being, a r<lin«_ r to mi ithorities, no 



lymphatic 



Considerable u has been taken in the Btimulat I which 



certain chemical Bubstances have on th< etion of lymph from 



thoracic duct. Th< called l>im.j>lnh; belong 



crystalline ami colloidal. Of the former, glucose, urea, and Bodium 

 chloride in hypertonic solution, are the l>«^t known. 81 - 

 their action as dependent upon an increase in the osmotic pi 

 the blood. This attracts water into the blood from ti 

 ami leads tu an hydremic plethora, with a consequent u ipil- 



larj ■ sure. It' the blood pressure is lowered by hemoi 

 the hypertonic Bolution is injected, little stimulation "t" lymph fl 



•us, l ause there is no available fluid in I 



plethora. This observation does not, how< 



tl xplanation, becau many other disturbai 



hemorrhage 



Tl ( illui<lal lymphagogues include watery exti 



sues of leeches, era} fish, and mua 



\ probably acl by damaging tin- endothelium «'f tl 

 that filtration occurs mon Although th 



more particularly on the lymphatics of tl 

 apparent on the skin capillaries, produi 

 tnation of Mi nettle rasl 



