Department of Anatomy, U?~iaer,vity of Oklahomz Srhoo7 of Xedicitze FOUR FIGURES X sccoiid series of aortic arches from macaques is here reported, all of the 153 speciii?ens being f roni rliesus monkey (Pethecus rhesus-Elliot, '13, or Jlacaca mulatta-Miller, '33). I n the first series of arches from 133 macaques (De Garis, '35) 115 spccimciis wei-e from 1'. rliesus, the remainder being from siiiicus, fascicnlaris, inis, mortlax a i d nemestrinus. Questions of terminology regarding tliese species have been dealt with in the 1935 report.
The animals from mliicli ao d i c a r c h of the preseiit report were taken have been snpplied from the Carnegie colony, Baltimore, supervised by Dr. C. G. Hartman axid from New I-Iavcn ilirougli the courtesy of Prof. J . 1'. E'nltoii. Specimens from tliese sour were kindly transmitted by Dr. A. H. Schultz, recorder of tlie Hopkiris aiiatomical collection. Large additions were also made by Dr. H. A. Hom-e, these being available in the coursc of his mork on 1)oliomyelitis at the Joliiis Hoplriiis Medical Scliool 1 lirough the Rooswelt Warm Springs E'tnicl. To all of the above contributors my thanks a r e due.
The series of aortic patterns describcd here is regarded as large eiiough f o r sigiiificant siatistical treatment, especially since all speeimcns arc from a siiiglr species. These patterns are classified 011 the basis of criteria established in the previous report, and as in that report tlieir incidence is represeiitccl by polpgoiis of freqnency.