THE LYMPH AND LYMPHATIC SYSTEM 341 



Star-fishes, and retaining quite a large development a 

 in the Vertebrates, is nowhere to be found. The swollen 

 blood-vessels have squeezed it out of existence, except 

 for certain sack-like remnants which enclose separately 

 the ovaries, and the testes, and the kidneys, and have 

 each its opening to the exterior conveying the products 

 of those important organs to the outer world. Thus we 

 gain a brief insight into the true history of the lymphatic 

 system and its vicissitudes in the lower animals and 

 in man. 



