1914 Science  
SCIENCE was made in 1908 and had been standing unchanged since that time. A general new culture of rotifers was made from these fertilized eggs and then a fern fcinales were selected at random and fed upon a continuous diet of the colorless P o l y t o m a in watch glasses. After a few generations a very high percentage of females were produced. At this period adult females were talcen froin several of the watch glasses and placed in some filtered water from a jar in which a general c,ulture of
more » ... general c,ulture of rotifers were thriving. Then there was added to this culture water the green flagellate, Du~zaliella. ous diet of P o l y t o m a to a diet of the green Dunalielba. Several other green flagellates have been reared arid used as food, but they do not seem to be effective in causing males to be produced. Many other observations are being made in a further study of the problem, and the detailed results together with the exact methods used will be published in a later paper.
doi:10.1126/science.39.1014.833 pmid:17821332 fatcat:l54id3skonexdh7eadvkcrozlm