The recent discovery that stem cells can be taken from amniotic fluid comes as positive news for all. Critics of the research should be cheered by any method that bypasses the use of embryos, as this one does. And supporters must take heart from any kind of advance in this promising field. The findings remain preliminary, however. And though they should be vigorously pursued, they should not prevent continued research on embryonic stem cells as one way of fighting disease.

As reported in the journal Nature Biotechnology, scientists at Wake Forest and Harvard universities found that they could safely draw stem cells from the amniotic fluid in pregnant women. The fluid cushions developing fetuses, and is commonly drawn during amniocentesis, a diagnostic procedure.

But amniotic stem cells, though plentiful, may not be able to develop into the full range of cell types that embryonic stem cells provide. Because they are only a few days old, embryonic cells are extremely flexible in terms of what they might become. Adult stem cells, championed as a good-enough alternative by foes of embryonic-stem-cell research, hold promising but probably limited uses (for instance, helping repair bone fractures). Difficult to extract, they are taken from living people, and considered unlikely to help with complex ailments. Amniotic cells look better, but may still fall short of what embryonic stem cells can do.

In 2005, Congress passed a measure that would have loosened President Bush’s federal funding restrictions on stem-cell research. It issued in the first veto of his administration. It also helped drive some Democrats into office last fall: Polls show strong support for the research.

Last week, the House passed the same bill, but not by a veto-proof margin. The Senate is likely to follow suit. It would be a shame if the president held onto his position, when so much good stands to be done through all forms of stem-cell research.

Anthony Atala, the author of the study on amniotic fluid, has said it is “essential” that the National Institutes of Health make research dollars available for embryonic stem-cell research. He sees the amniotic-fluid approach as complementary to it, not as a replacement. For one thing, embryonic-stem-cell research is further along, and closer to being tested in humans. In moving toward possible cures, time is of the essence.

The legislation just passed would use five-day-old embryos left over from fertility clinics, and donated by parents. They would otherwise be destroyed. Given its potential to help rout such diseases as diabetes, Parkinson’s and more, embryonic-stem-cell research should be funded.