TADPOLE RAISED BY ARTIFICIAL PARTHENOGENESIS. 21& 
Note on the Sex of a Tadpole raised by 
Artificial Parthenogenesis. 
By 
J. Bronte Gatenby, B.A., 
Exhibitioner of Jesus College, Oxford. 
With 5 Text-figures. 
With the object of ascertaining what is the sex of tadpoles 
of It. temporaria raised by artificial parthenogenesis [ I 
undertook some experiments last April. As my intention was 
to procure as many tadpoles as possible, I adhered to the 
method of smearing the eggs with a mixture of blood and 
lymph and then pricking each one with a very fine glass 
needle. The usual precautions were taken in this work, even 
the water in which the eggs were raised being drawn from a 
tank where it had remained for several days; the frogs were 
carefully washed in alcohol before opening, and the eggs were 
not allowed to touch the skin while being withdrawn from 
the swollen uterus. 
Two sorts of glass needles were used ; one was drawn from 
glass tubing and the other from solid glass rod; the former 
gave a higher percentage of burst and spoilt eggs, but while 
the latter sort of needle gave fewer irretrievably ruptured 
eggs, the percentage of successful segmentations was lower. 
There is little doubt that the minute lumen left in the glass- 
tube needle served to introduce more of the blood and lymph 
into the egg, and hence to promote segmentation. In some 
experiments carried out by the late Dr. Jenkinson different 
