LYMPHATICS IN FROG LARVAE 5 



Two recent reviews (1933, 1934) should be noted here as 

 giving the best general accounts of the comparative anatomy 

 and embryology of the lymphatics of vertebrates brought up 

 to date. 



The memoir of H. Hoyer of Krakau, Poland ('34) is cer- 

 tainly of first importance, as it brings together in an excep- 

 tionally able manner his own many valuable contributions on 

 the lymphatics of lower forms, with those of his active group 

 of students, as well as the results of other authors. There 

 is thus furnished an authoritative guide for this field of in- 

 vestigation in which excellent characterizations and schemata 

 are given for the types of distribution of the lymphatic system 

 in the different groups of vertebrates. The need of such pic- 

 tures of final stages to indicate the objectives in studies of 

 the embryology of different types is pointed out, and the 

 development is discussed for each group. Valuable critical 

 analyses are included on controversial topics, and many illus- 

 trations and full bibliographies accompany each section of 

 the memoir. 



The other best general review of recent date forms a chap 

 ter on lymphatics by Weidenreich, Baum and Trautmann in 

 the Handbuch d. Vergleichende Anatomie d. Wirbelthiere, vol. 

 VI, edited by Bolk, Goeppert, Kallius and Lubosch, 1933. 

 Extensive treatment of the literature is included. 



COMPARISON OF RESULTS OF DIFFERENT METHODS OF 

 INVESTIGATION 



In addition to these general reviews of the literature a 

 number of controversial papers which affect our own work 

 should be examined particularly. These fall into two groups 

 stimulated by Doctor Sabin's original claim ('01) that her 

 injections prove that the lymphatics come from certain veins 

 and grow centrifugally through the body. A series of investi- 

 gations were soon published disputing these conclusions and 

 contending for an origin of the lymphatics from peripheral 

 tissue spaces with consequent centripetal growth to join the 

 veins. For these papers reference should be made to the 



