/,'. - abin. 



I thai the periphera] capillaries grow entirely 



then it is a perfectly logical h 



lymphal . from the veins, from to periphery, 



r than from the periphery to the veins. This h - was 



Ranvier (113), based on the evidence of the m( i ■ i »>d of 



growth "f the lymphatic capillaries within the peripheral pl< 



r i 110-118), in a Beries of Btudies between the years L895 and 



injection aphatics in a varii ty o For 



example, he injected the exceedingly abundant plexus in I otery 



foetal pig 10 cm. long, as well as in the ral and rabbit. Ee also 



the lymphatics in the amphibia. Thes im an 



of the form of the develi 

 • - looking like collarettes in the. walls of lymphatic ducts, the 



with blunt terminal kn which 



■ g are often found in tl is well be 



ts, either ending free or as bridging a gap in the aetwork to 

 another vessel. From all of these forms of growing lymphatics Elan- 

 saw that the growth nf lymphatics was from eenteT hew, 

 and even though he thought that the lymphatics did not begin in a 

 mammalian embryo until it v.. I L0 cm. long, a stage al which the 

 embryology of thi i may be called completi . aevertl went 



■ !\i'i-. for he deduced the 

 -!- that the lymphatics grow from the veins. He likened 

 growth to the growth of a gland (113). In mj own work 1 was led 

 to the same view by tracing the lymphatics in and younger 



embryos hack to the veins, and the next section will include thi 

 .:■ oce which 1 regard as essential to establish the hjTpothesis of Ranvier 

 as the correel theory of the origin of the lymphatic system. Tl 

 count of the evidence for growth b is, however, not yet 



complete. As far as the evidena e obtained by the observation 



of injected specimens, it was especially well described and figured 

 by MacCailum (79). He added the observation of watching thi 

 jection in »scope and showed that extravasations are due 



cplosive rupture of the lymphatic wall, 

 [njected specimens of developing lymphatic capillaries are now 

 well known; excellent fig given by Bartels ( I d 10, 



p. 43). They show a large number of sprouts, I" ley are taken 



from the skin of a iryo 6.5 cm. long. 'I xacl 



lary, superficial, Bne-meshi d pli jus iwing 



