i 4 POPULAR SCIENCE MONTHLY 



within the last twenty-five years, the best known and probably the 

 most important, certainly the most spectacular and unforeseen, is the 

 revelation of the structure of the nervous system and of the relation 

 of the nerve cells to one another. This wonderful achievement has 

 been due chiefly to the introduction of a single new method, named 

 after its inventor Golgi, one of those brilliant modern men who prove 

 that genius is still the gift of the Italian race. He was born at Cor- 

 teno on the ninth of July, 1843. The method was first described 

 in 1875 in an article on the fine structure of the olfactory bulbs. The 

 method was so radically different from anything known at that time 

 that it was treated with scornful incredulity, and no attention was 

 paid to the new invention which was destined to revolutionize our 

 knowledge until it was introduced in Germany by Professor Kolliker 

 in 1887. This marvelous method has been found to work best with 

 embryos and has enabled us to trace out the form, including their 

 ramifications, of the nerve cells and neuroglia cells of the brain and 

 spinal cord throughout their whole period of development. As you 

 know, all our contemporary teaching in regard to the structure and 

 functions of the central nervous system, our conceptions of the nervous 

 mechanism within the central nervous system and in the ganglia, are 

 based upon the results obtained through the application of Golgi's 

 method by embryologists. It is pleasant to note that in 1903 the 

 completion of twenty-five years of teaching, and, by a happy coinci- 

 dence, the anniversary of his silver wedding, were celebrated by Pro- 

 fessor Golgi's pupils by the publication of his complete works, ' Opera 

 Omnia,' in three magnificent quarto volumes. Copies of this pub- 

 lication ought to be in every pathological and histological laboratory 

 in the world. Indeed, every text-book of anatomy, embryology or 

 pathology published now-a-days is a memorial of Professor Golgi, for 

 they are all abundantly supplied with figures of Golgi preparations. 

 We may see in this history an illustration both of the value of the 

 embryological data and also of the almost" creative power of a new 

 method. 



Degeneration has long been regarded as essentially a patho- 

 logical process. This is the view which we have inherited. 

 Nevertheless it is incorrect, as has been demonstrated by the more 

 exact study of normal cytomorphosis during recent years. We now 

 know that degeneration is to be looked upon as a normal end to a 

 complete cytomorphic cycle. Instances of normal degeneration have 

 long been familiar to us. Our mistake has been in overlooking their 

 interpretation, their significance as part of the normal life. Thus 

 the horny layer of the skin is made up of degenerated cells. Cartilage 

 when it is replaced by bone undergoes a normal degeneration. In 

 short, we must regard pathological degeneration very much as we re- 

 gard those plants which we call weeds, things which are growing 



