PERSISTENCE OF A VEIN IN XENOPl'S LABVJS. 415 



the {x^stcaval. which portion must surely have arisen from a 

 fusion of the two inter-renal portions of the postcardinals of 

 lower forms. (,)ne is practically forced to this view because of 

 the fact that, in many fishes, the two inter-renal portions of the 

 post cardinals are joined to one another by transverse connec- 

 tions, which connections one can easily suppose to have expanded 

 more and more, so as eventuall}' to become confluent, and so 

 bring these two portions of the postcardinals into direct connec- 

 tion with each other alonij their whole length. 



SUMMAR^■. 



1. The specimen considered is an adult female of Xenopns 

 hnns, found in the vicinity of Johannesburg. 



2. It was peculiar in that the postcaval was absent, and 

 there was present an additional vein on the right side correspond- 

 ing to tile right posterior cardinal of fishes. 



3. Similar abnormalities have been described in Rana fcin- 

 poraria by Howes and by Parker. 



4. This persistence of the posterior cardinal probably heljis 

 to explain the origin of the postcaval of amphibious and higher 

 vertebrates, and consequently helps to support the view brought 

 forward by Hochstetter in 1887. 



References. 



Balfour, i^ \L: " Comp. Embryolog}'," 2 (1881). 538. 



Dreyer, T. F. : Trans. Roy. Soc. S. Afr.. 4 (1914-15), 253. 



Hochstetter: Morphol Jahrhuch, 13 (1887-8). 



Howes, G. B. : " Note on the azygos veins in anurous am- 

 phibia." — Proc. Zool. Soc. (1888), 122-126. 



Parker. W. N. : " On the occasional persistence of the left 

 posterior cardinal vein in the Frog, with remarks on the homo- 

 logies of the veins in the Dipnoi." — Proc. Zool. Soc. (1889), 

 H5-I5I- 



Zoological Department, 



South African School of Mines and Technology, 

 Johannesburg. 



The Pandemic in the United States. — The 



United States Bureau of Census has just issued a statement with 

 reference to the mortality from influenza and pneumonia in 

 several large cities in the States during the 19 weeks commencing 

 September 14, 1918. The total death-roll fromthis cause was 

 127,503. Of these 27,436 deaths occurred in New York, 14,326 

 in Philadelphia, and 12,300 in Chicago. 



