. The American journal of anatomy . ). Inolder specimens the interventricular foramen is just closed andthe bundle reaches to it from the region of the sinus. Two limbsare easily outlined one of which reaches to the moderator band ofthe right ventricle, which is pronounced in the human embryo. The atrio-ventricular muscle is well lodged between the valveand the annulus fibrosus in an embryo 18 mm. long (432, fig. 21);it again extends into the moderator band. The same is observed DEVELOPMENT OF THE HUMAN HEART 291 in another specimen of the same size and prepared in the same way(No. 43, mm
. The American journal of anatomy . ). Inolder specimens the interventricular foramen is just closed andthe bundle reaches to it from the region of the sinus. Two limbsare easily outlined one of which reaches to the moderator band ofthe right ventricle, which is pronounced in the human embryo. The atrio-ventricular muscle is well lodged between the valveand the annulus fibrosus in an embryo 18 mm. long (432, fig. 21);it again extends into the moderator band. The same is observed DEVELOPMENT OF THE HUMAN HEART 291 in another specimen of the same size and prepared in the same way(No. 43, mm. long). At this stage the nerves have reachedthe region of the sinus as is seen in specimen (460, 21 mm. long).In this specimen the bundle can be followed by the spaces aroundit, figs. 27 and 28. Another specimen (368, 20 mm.), which isunusually well preserved to show the fibrillae of the heart muscle,shows that the degree of development of the atrio-ventricularbundle is the same as that of the rest of the musculature of
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectanatomy, bookyear1912
