The Origin and Development of the Lymphatic System. 53 



-C.L.D. 



Fig. 15. — After E. L. Clark. Lateral view of the jugular lymphatic plexus 

 of the right side of a chick embryo 14 mm. long after an incubation of 5 

 days and 20 hours. The measurement was the greatest length and was 

 taken after fixation. With a very fine canula (the lumen of the point being 

 about 15 n in diameter) diluted India ink was injected under a binocular 

 microscope into one of the superficial lymphatic capillaries in the skin 

 between the fore and hindlegs. From here the ink filled the deep jugular 

 lymphatic plexus, and from there a few granules entered the vein through 

 five connections (C). The drawing was made with the help of a camera 

 lucida with a Zeiss binocular microscope (oculars No. 4, objective A s ). 

 Magnified 67 times. A. = vessel which connected the superficial lymphatic 

 catiilla.ripa twi+Ti tho inmilor ivmn>i nlovna nnH whiph was im'er.f.erl : A. C. — 



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