February 2006 issue of the Cornell Flower Bulb Research Program Research Newsletter:
Many are familiar with the unusual problem of “spitting” in hyacinths. Spitting is a cultivar specific problem (mostly with blue cultivars), whereby the entire flower bud and stem below it become physically detached from the top of the base plate inside the bulb. The result is that the bud is carried upwards as the leaves grow. The bud stops enlarging quickly, due to the lack of water. Eventually, as the bud continues to lose water, it is noticeable as a loose bud, that can be plucked out of the leaf sheath.
Read the whole article. Starts on page 4.