330 The Development of the Counective Tissues 



by Spuler/ and the reader interested in this side of the question is 

 referred to it. 



My own studies upon the development of connective-tissue fibrils 

 began a number of years ago and my first results were published in 

 1891/ Up to that time I could make but little headway with sections 

 prepared in the ordinary way, and was compelled to use frozen sections 

 and chemicals to analyze them. By using these methods alone I think 

 all observers will also come to the conclusion I did at the time — that 

 the connective-tissue fibrils are intercellular in their formation. Since 

 that time, however, methods have been improved and I have gradually 

 learned that the development of white fibrous tissue is better studied 

 in the skin and superficial fascia of the embryo than in tendons, and 

 that elastic tissue is better studied in the arteries and in elastic cartilage 

 than in the ligamentum nuchas. I also have found that in their develop- 

 ment the reticulum of the liver, the connective tissue of the cornea and 

 cartilage are practically identical with that of white fibrous tissue. 

 Very recently Dr. Sabin, Fellow in Anatomy at the Johns Hopkins 

 University, has followed successfully the development of the reticulum 

 of the lymphatic node. While ray results are now decidedly in favor 

 of Flemming's view, the reader will soon see that if other methods and 

 interpretations are employed (which I now consider false), it will be 

 quite as easy to see the fibrils developing between the cells as within 

 them. 



This all brings me to a turning point, no doubt the key to the situa- 

 tion. The network of fibrils which forms Wharton's tissue, to employ 

 the best known example, is composed of a mass of anastomosing cells, a 

 syncytium, from which the connective tissues arise. Often this syncj''- 

 tium is very sharply defined and differentiated, with nuclei and a little 

 protoplasm which is less differentiated lying upon it. When differ- 

 entiated to so great an extent it is very easy to designate the main 

 portion of the syncytium as intercellular in position as well as in origin ; 

 and since the connective-tissue fibrils arise directly from it they are of 

 course intercellular in origin. When studying these structures in 

 frozen sections it is quite easy to remove the nuclei, leaving only the 

 fibrils of the syncytium. With improved methods, however, it can be 

 shown that in later stages of the development of the syncytium the 

 nuclei lie upon it and are therefore easily removed. In the earlier 

 stages the nuclei lie within the syncytium, but at this time it is too 

 delicate to isolate by the freezing method. 



*Spuler, Anatom. Hefte, Bd. 7, 1896. 



5 Mall, Abhandl. d. K. S. Gesellscli. d. Wiss , Bd. 17, 1891. 



