. Anatomischer Anzeiger. Anatomy, Comparative; Anatomy, Comparative. 376 Aorta Postcava renalis In a single specimen of Tragulus meminna (Erxleben) recently examined by the writer, however, the postrenal division of the post- cava was found to lie ventral to the aorta and to be formed caudally through a union of the common iliac veins which takes place ventral to the aorta (Fig. 2). As only one specimen of Tragulus was examined one cannot be certain that the postcava in this particular case represents the normal conditions; whether it be normal or abnormal, however, the type of postcava presen
. Anatomischer Anzeiger. Anatomy, Comparative; Anatomy, Comparative. 376 Aorta Postcava renalis In a single specimen of Tragulus meminna (Erxleben) recently examined by the writer, however, the postrenal division of the post- cava was found to lie ventral to the aorta and to be formed caudally through a union of the common iliac veins which takes place ventral to the aorta (Fig. 2). As only one specimen of Tragulus was examined one cannot be certain that the postcava in this particular case represents the normal conditions; whether it be normal or abnormal, however, the type of postcava presented by this single specimen is certainly unusual for ruminants and, so far as known to the writer, has not been hitherto recorded as occurring in the same. The postcava of Tragulus appears to represent a case of double or bifurcated postcava. It differs, however, from the type of double postcava occasionally met with as an abnormality in man, the cat and the rabbit, and, which is con- stant in the Indian ele- phant and Dasypussetosus (Fig. 3), in that the com- mon iliac veins (paired portion of postcava) do not unite to form the unpaired portion con- tiguous to the openings of the renal veins, but rather at a point some- what caudal to this level. A type of postcava similar to that found in Tragulus has also been described by Hochstetter i) as occurring in Dasypus novemcinctus (Fig. 4). In this case Hochstetter accounts for the presence of an unpaired portion of the postcava caudal to the openings of the renal veins, as due to the circumstance that, be- tween the latter and its point of bifurcation, the postcava undergoes an extensive elongation in correlation with a rapid growth of the lumbar portion of the vertebral column. In the opinion of the writer this explanation is probably correct, not only in the case of Dasypus. A. iliaca ext. V. iliaca ext. iliaca int. A. iliaca int. Fig. 3. Postrenal division of the postcava of Dasypus setosus. After HOCHSTETTEE. Adult. Ven- tral
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