58 ANATOMY OF THE LYMPHATIC SYSTEM. 



CHAPTER IV. 



THE BLOOD-VESSELS OF THE SEROUS MEMBRANES. 



THIS is the last subject we shall have to treat of in the section 

 concerning normal structure. We shall pass over the distribution of 

 the blood-vessels in general^ as this is so well known and so simple that 

 we should only weary the reader were we to bring it forward here. 

 We shall only consider two points in this chapter ; first, the distribu- 

 tion of blood-vessels in the lymphangial nodules and cords; and 

 second, the development of blood-capillaries. It is especially the 

 latter to which we desire to draw the attention of the reader. We 

 have already mentioned, at the commencement, that in the omentum 

 and pleura a growth and new formation of lymphatic nodules takes 

 place, all of which gradually become furnished with a distinct blood- 

 vascular system, which itself grows with the growth of the nodules,, 

 and in which the capillaries especially are very richly distributed. 

 We can therefore observe in these places a continuous increase and 

 new formation of vessels in the adult organism in the normal state. 

 Concerning the first point, viz. the distribution of blood-vessels in the 

 lymphatic nodules and cords, we have to say what follows. Wherever 

 in a nodude or cord a blood-vascular system can be observed, it con- 

 sists in general of an afferent small arterial branch, and one or even 

 two small efferent veins, between which is a network of capillaries, 

 which is more or less close, according to the size of the nodule. In 

 isolated cases only a variation may be noticed, where there are two 

 small arteries and only one vein. I refer the reader to the figures, 

 which although they represent pathological preparations, are com- 

 pletely identical so far as the distribution of blood-vessels is concerned, 

 with full-grown normal nodules. We may often see, coming off from 

 a small artery which is distributed to such a cord or nodule, a capillary 



