TimesMachine is an exclusive benefit for home delivery and digital subscribers. Full text is unavailable for this digitized archive article. Subscribers may view the full text of this article in its ...

Paramecium or paramecia are single-celled protists that are naturally found in aquatic habitats. They are typically oblong or slipper-shaped and are covered with short hairy structures called cilia.

In the animal kingdom, reproduction is a necessary part of species survival. Parthenogenesis, a form of asexual reproduction where embryos develop from unfertilized eggs, has been observed in captive ...

The history of life stretches back untold eons. Today, there is a staggering array of organisms on Earth, with more species being discovered every year. The complexity of life, from the smallest ...