412 OTTO F. KAMPMEIER 



occur only at a definite period and place, and only in connection 

 with those venous channels which have become detached from the 

 main venous trunks and no longer serve in the economy of the 

 blood vascular system. 



Last year there appeared in monograph form the first two parts 

 of Huntington's investigations on the anatomy and development 

 of the systemic lymphatic vessels in the cat. 18 Besides its great 

 detail, the work is profusely illustrated with convincing micro- 

 photographs and reconstructions and is a very positive and elabor- 

 ate confirmation of the theory of the direct mesenchymal origin 

 of all lymph ducts. Once more he emphasizes sharply the analogy 

 between the blood vascular and lymphatic systems in their earliest 

 anlagen, both beginning their history in a similar manner and in 

 the same soil. The first blood vessels arise in and amongst the 

 strands and 'blood islands' of the mesoderm as intercellular clefts 

 and fissures which enlarge, elongate and flow together to create a 

 network of intercommunicating channels. Their boundaries at 

 first are the unspecialized and cuboidal mesodermal cells among 

 which they lie. The fluid which fills their cavities and which is 

 perhaps secreted by these cells is evidently under a certain pres- 

 sure and exerts its influence in the modification of the immediate 

 or limiting walls into a vascular endothelium. The cells by a 

 mechanical adaptation to this pressure lose their cuboidal form 

 and become flattened and scale-like. Likewise the lymphatic 

 anlagen begin as intercellular spaces and enlarge, elongate and 

 coalesce into continuous vessels, and like the intima of the blood 

 vascular anlagen their intima is a differentiation of the cells 

 among which they are formed. 



After such general considerations, Huntington enters into a 

 very complete description of the development of the thoracic 

 duct. Because a resume of this history, as determined by him, 

 has already been given in the review of an earlier paper, it need not 

 be repeated here. Suffice it to say that nowhere has he found the 



18 George S. Huntington: The anatomy and development of the systemic lym- 

 phatic vessels in the domestic cat. Part I. The development of the systemic 

 lymphatics in their relation to the blood vascular system. Part II. The develop- 

 ment of the pre-azygos and azygos segments of the thoracic duct. Memoirs of the 

 Wistar Institute of Anatomy and Biology, May, 1911. 



