The nature of the sparing phenomenon. IV. The role of complement in the hemagglutinin-inhibition phenomenon. Elery R. Becker 461

Distribution in the young dairy calf of orally administered P³² . R.H. Olson, R.S. Allen and N.L. Jacobson 467

Developmental morphology of the inflorescence and flower of Trifolium pratense L. Warren E. Picklum 477

Lipid phosphorus in calf blood plasma. J.H. Zaletel and R.S. Allen 497

Factors affecting germination of Kentucky bluegrass seed. Louis N. Bass 503

Noxious weed seeds. Duane Isely and W.H. Wright 521

The history of the bud graft union in roses. Griffith J. Buck 587

Initiation and development of the inflorescence of Phalaris arundinacea L. and Dactylis glomerata L. Imy Vincent Holt 603