RECENT PROGRESS IN PHYSIOLOGY. 449 



flueed ; and if in this lie has been outstripped and even corrected by 

 others, his original merit must not be allowed to be forgotten. Those 

 others are many, in manj^ lands; but two names stand out conspicuous 

 among them. If rejuvenescent Italy invented the method, another 

 ancient country, whose fame, once brilliant in the past, like that of 

 Italy, suffered in later times an eclipse, produced the man who, above 

 all others, has shown us how to use it. At the meeting at Montreal a 

 voice from Spain telling of things physiological would have seemed a 

 voice crying out of the wilderness; to-day the name of Ramon -y-Cayal 

 is in every physiologist's mouth. That is one name, but there is yet 

 another. Years ago, when those of us who are now veterans and see 

 signs that it is time for us to stand aside were spelling out the primer 

 of histology, one name was always before ns as that of a man who 

 touched every tissue and touched each well. It is a consoling thought 

 to some of us elder ones that histological research seems to be an anti- 

 dote to senile decay. As the companion of the young Spaniard in 

 the pregnant work on the histology of the central nervous system done 

 in the eighties and the nineties of the century must be named the 

 name of the man who was brilliant in the fifties, Albert von Kolliker. 

 When I say that the progress of our knowledge of the central nervous 

 system during the past thirteen years has been largely due to the appli- 

 cation of the method of Golgi, I do not mean that it, alone and by itself, 

 has done what has been done. That is not the way of science. Almost 

 every thrust forward in science is a resultant of concurrent forces 

 working along different lines; and in most cases at least significant 

 progress comes when efforts from different quarters meet and join 

 hands. And especially as regards methods it is true that their value 

 and effect depend on their coming at their allotted times. As I said 

 above, neither experimental investigation nor clinical observation nor 

 histological inquiry by tlie then known methods had been idle before 

 1880. They had, moreover, borne even notable fruits, but one thing- 

 was lacking for their fuller fruition. The experimental and clinical 

 results all jiostulated the existence of clear, definite paths for impulses 

 within the central nervous system — of paths, moreover, which, while 

 clear and sharp, were manifold and, under certain conditions, alternate 

 or even vicarious, and were so constructed that the impulses as they 

 swept along them underwent from time to time — that is, at some place 

 or other — transformations or at least changes in nature. But the 

 methods of histological investigations available before that of Golgi, 

 though they taught us much, failed to furnish such an analysis of the 

 tangle of gray and white matter as would clearly indicate the paths 

 required. This the method of Golgi did, or rather is doing. Where 

 gold failed silver has succeeded, and is succeeding. Thanks to the 

 black tract which silver when handled in a certain way leaves behind 

 it in the animal body, as indeed it does elsewhere, we can now trace 

 out, within the central nervous system, the pathway afforded by the 

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