484 



Ealph H. Major. 



Fig. 3 was drawn. The general scheme of these anatomoses varies 

 considerably in the different human thyroids. Landstrom, in his 

 article to which reference has previously been made, gives excellent 

 drawings of some of these variations. 



In the human thyroid, few large arteries are present in the depths 

 of the gland, and in this respect it differs from the dog. In other 

 words, in the human the branching of the large arteries takes place 

 mostly upon the surface of the gland, and having by their branching 

 obtained their approximate distribution, the smaller branches are 

 sent in. 



Fig. 5. — Drawing illustrating arteries of third order passing between lobules 

 and arteries of fourth order supplying the lobules in the human thyroid 

 (partly diagrammatic). 



The further distribution of the arteries is essentially the same in 

 both the dog and man. The arteries of the third order, as is shown 

 in Fig. 5, pass between the lobules and give off arteries of the fourth 

 order which supply the lobule. Each lobule is composed of a num- 

 ber of follicles and is supplied usually by from two to five arteries, 

 the number of arteries depending upon the size of the lobule. 

 Fig. 6 and Fig. 7 show two lobules which have been dissected out 



