CONTENTS. 



No. 24. The developmental alterations in the vascular system of the brain of the human 



embryo. By George L. Streeter (5 plates, 12 text-figures) 5 



25. The mitochondrial constituents of protoplasm. By E. V. Cowdry (1 plate, 9 



text-figures) 39 



26. The development and reduction of the tail and of the caudal end of the spinal cord. 



By K.\NAE KuNiTOMO (4 plates, 2 text-figures) 101 



