MEDICINE IN MODEKN TIMES. 703 



But, in spite of all this, I am inclined to think that the direct action 

 of nerves on cells is a vera causa ; and, even if our highest micro- 

 scopic powers do succeed in proving that nerve-tissues are never 

 continuous with any other tissues in any part of their distribution, 

 it must still be recollected that such intervals as may be demon- 

 strated will be, if not insensible, at all events infinitesimal ; and 

 nerve-force may well be sufficient to act across such gaps as these. 

 (See Dr. Radcliffe's ^Lectures on Epilepsy,' 1864, pp. 13 and 330.) 

 I can appeal for my justification to Professor Lister's experiment, 

 recorded in his paper on the Cutaneous Pigmentary System in the 

 Frog ('Phil. Trans.^ 1858, pp. 636-639), in which certainly the 

 nerve-system is shown to have some control over the molecular 

 movements of concentration and difi'usion quite independently of 

 the blood-vascular system. The cessation of the circulation in a 

 frog's web entails the concentration of the pigment ; therefore 

 Professor Lister took a pale frog — i. e. one in which the pigment 

 was already concentrated; and, tying a ligature above the ankle, 

 so as to eliminate the condition of cessation of the blood's circu- 

 lation, he then eliminated the condition of nerve-influence from the 

 cranio-spinal axis by amputation above the ligature. Cessante causa, 

 cessat et effectus ; the nerve-force is removed ; and the pigmentary 

 diffusion which it had held in check is set up and continues, until 

 superseded by the post mortem concentration which ordinarily takes 

 place, and produces that lightening of the dark hue usually seen in 

 the frog after death. This experiment, which I have not given in 

 full, nor in Professor Lister's own words, is a very striking one ; 

 and I hope I may remark, without offence to any representatives of 

 the German Fatherland, to which physiology owes so much, that 

 much that has been recently written and worked at there might 

 have been spared, had Mr. Lister's papers been as well known to 

 them as they will be to their successors. They seem to me to mark 

 an era in the literature and in our knowledge of the essence of 

 inflammation. 



Here, if I may be allowed to digress somewhat, I would remark 

 that Professor Lister's suggestion made in 1858 (loc. cit. pp. 619 

 and 640) as to the probability of the existence in the limbs of a 

 ganglionic apparatus co-ordinating molecular and other movements 

 at the periphery, sometimes independently, sometimes subordinately 

 to the cranio-spinally placed nerve-centres, may seem to have found 



