26 HARRIETT M. ALLYN. 



Tables I.-III. show a list of the agents employed, with the 

 varying degrees of success. As stated in Table I. swimming 

 larvae may be induced in unfertilized eggs by the use of potassium 

 chloride, sodium chloride, hydrochloric acid, acetic acid, butyric 

 acid followed by sodium chloride, sodium hydroxide and sodium 

 chloride, alcohol, potassium chloride followed by hydrogen or 

 by oxygen-saturated sea -water, or by de-aerated sea-water, low- 

 temperature, high-temperature, or oxygen-saturated sea-water. 

 Probably there is a large number of other agents also which 

 would bring about the same result. The majority of the above 

 may be made to induce polar body formation only, if shorter time 

 or lower concentration is used (see Table II.). Potassium 

 cyanide, and de-aerated sea-water, both induced polar bodies 

 only, no matter what time or concentration was used. The same 

 agents may prove altogether ineffective in inducing development 

 when used in certain other concentrations and times. Sulphuric, 

 nitric, and oxalic acids, were also found to be ineffective, as well 

 as sperm extract (by boiling), and mechanical agitation and 

 injury (by shaking with ground glass) (Table III.). Many of 

 the experiments were performed merely to obtain a "lead," and 

 if the results did not appear suggestive that line of work was 

 abandoned. If they appeared suggestive the experiment was 

 usually repeated with some changes. 



Considerable variation was noted in the behavior of different 

 lots of eggs under similar conditions of experimentation. Just 

 what the conditions are which govern this variation I have not 

 been able to discover. Sometimes the female did not appear to 

 be in good condition, but this was not a universal test by any 

 means. Variations in results under uniform conditions seem 

 to be characteristic of experiments in artificial partheno- 

 genesis. 



C. Methods. The animals were brought to the laboratory in 

 their tubes. On removal from the tubes, the males and females 

 were kept in separate dishes in running sea-water, from twelve 

 hours upward. In some cases the females were washed in tap 

 water for one minute, before using, but this did not seem to be a 

 necessary precaution. On using, the sex segments were cut off, 

 the ovaries removed, and torn to pieces, and the eggs passed 



