50 C. IV. M. Poyntcr 



The external iliac may be double, Delitzin (1901), or may lie 

 lateral to the artery, Harrison (1839). 



The inferior epigastric vein may be double — I have seen three 

 cases — or may run through the femoral ring, Labatt (1838), or 

 connect with the obturator or pudendal, Dubrueil (1847), Redfern 

 (1850). 



Lower Extremity 



There are few records of anomalies of the veins of the lower 

 extremity and those I have picked up are of such minor character 

 as to hardly claim our interest. A double popliteal has been re- 

 ported as an anomaly, but Robinseau (1897) found the condition 

 present in 17 of 20 subjects examined; I did not find such a high 

 frequency, 40 per cent., but agree with him that it is not to be 

 classed with anomalies. Certain irregularities, of course, and con- 

 nections have been mentioned by Ouain (1844), Langer (1867), 

 Giovanardi (1879), Davidson (1890), Gruber (1872), Altuchow 

 (1895), Focacci (1904), Dienlafe (1904). 



GENERAL SUMMARY 



Certain impressions are gained from a general survey of vascular 

 variations and their literature which seem worth while to include 

 in this study. 



Variations are found within certain limits which, in the great 

 majority of cases, exactly correspond to developmental stages and 

 represent either abnormal persistence or atrophy of channels. 

 They are not as variable as Baader's capillary theory would imply, 

 consequently must belong to a later stage of development, or else 

 the early capillaries are precursors of, rather than a stage in, the 

 development of the vascular tree. 



Vascular anomalies belong with other teratological conditions 

 and their etiology is probably the same as that of other develop- 

 mental irregularities. 



There seems to be little information of a basic character to be 

 gained from the study and tabulation of these anomalies ; however, 

 our interest in them will probably continue because of their in- 

 frequency. 



