54 PATHFINDERS OF PHYSIOLOGY 



bom at Bordeaux, France, in 1783, studied medicine in Paris, where 

 he became demonstrator, and eventually professor of anatomy in the 

 College of France. He died in 1855. ^ 



Magendie is described as being abrupt in manner, even to rude- 

 ness. His brusque manner has been referred to in his relations with 

 his understudy, Claude Bernard. He seems, however, to have been 

 a brilliant if not very methodical worker. He refers to himself as 

 a ragpicker by the dust heap of science. His work on the nervous 

 system was parallel with that of Sir Charles Bell, and the scope of 

 the work of both is epitomized in the well-known Bell and Magendie 

 Law to the effect that the spinal roots may be divided into afferent 

 and efferent, the anterior roots carrying impulses only from the 

 spinal cord to the periphery, while the posterior roots carry impulses 

 from the periphery to the central nervous system; a nerve fibre can- 

 not be both motor and sensory; we may have both nerve fibres in a 

 single nerve trunk but the fibres in each case are isolated and con- 

 duct impulses only in one or other direction. 



To Claude Bernard, associated with Magendie in the College 

 of France, we owe the discovery of the vaso-motor nerves. 



Broca and the "Speech Center." — In 1861 Paul Broca, an immi- 

 nent French surgeon, proved that there is a definite locality in the 

 brain which is the seat of articulate speech. This is known today as 

 "Broca's Convolution." Nine years later, thanks to the labors of such 

 men as Hitzig, Ferrier and Charcot, it was shown that each of the 

 special senses has its anatomical seat in the brain. It was also found 

 that each volutary muscle or group of muscles could be made to con- 

 tract by the excitation of certain "centers" or localities in the surface 

 of the brain. Regarding later progress in brain physiology, Gorton 

 says: "It is worth while to note the stride anatomy has made dur- 

 ing the closing years of the nineteenth century, especially in knowl- 

 edge of the central nervous system of man and animals. Early in the 

 last decade of the century the subject was taken up by German and 

 Italian anatoniists, Waldeyer, Nissl, Marchi, Golgi, His, Apathy and 

 others. To Waldeyer we are indebted for the doctrine of neuron as 

 applied to nerve cells, from the Greek word "neuron,' signifying unit. 

 According to this doctrine every cell is a unit having an independent 

 existence, distinct and apart from other cells, though related to them, 

 and may degenerate and die without affecting the existence of the 

 others. Meynart estimates that "the cortex of the cerebral hemis- 

 pheres ^lone <;ontains_twelve hundred millions of ganglionic cells;" 

 and Donaldson states that three thousand miltion: cells "is a modest 

 estimate of the total number of these neurons in the central nervous 

 system." The doctrine of neurons has been assailed as applied to com- 

 parative histology by the distinguished Apathy, and defended among 

 others by Barker, of Johns Hopkins University." The invention of 

 staining processes afforded a powerful impetus to the study of nerve 

 tissues. 



By means of animal experimentation Flourens, Luciani and 

 Horsley determined the function of the cerebrum. Removal of the 

 cerebrum from a frog or pigeon caused all its voluntary movements 

 to cease, but did not interfere with the reflexes or the negative func- 



