330 RALPH S. LILLIE. 



placed in the following solutions: (i) pure 0.55 NaCl, and (2-10) o.55m NaCl 

 containing anaesthetics as follows: (2-4) ether, 0.6, 0.45, and 0.3 volumes per cent., 

 (5-7) chloral hydrate, 0.6, 0.4 and 0.2 per cent., (8-9) chloroform, one sixth and 

 one tenth saturated, and (10) ethyl alcohol, 5 volumes per cent. After three hours 

 and fifteen minutes in these solutions the eggs were transferred to normal sea-water 

 and washed free of the anaesthetics by two changes of sea-water; spermatozoa were 

 then added. At the same time spermatozoa were added to the untreated eggs 

 which had remained in sea-water. The result- were as tollows: of the control eggs, 

 fertili/ed in sea-water without treatment, almost all died before reaching the blastula 

 stage; only a few feeble blastulae (a fraction of i per cent.) were found on careful 

 search; many eggs failed to cleave or even to form membranes. The eggs exposed 

 to pure 0.55/n NaCl also formed few blastulae, but these were relatively somewhat 

 more numerous as well as more active than in the control; the eggs treated with 

 0.55JW NaCl containing 0.45 and 0.3 vol. per cent, ether, especially the latter, showed 

 a more decided improvement over the control, though the proportion of blastulae 

 was still small. The eggs from the other solutions showed no improvement. 



A similar result was observed in a second series of experiments 

 with eggs which showed similar peculiarities. Eggs treated 

 for three hours with o.55w NaCl containing 0.3 vol. per cent, 

 ether gave about 5 per cent, of blastula, while of the control 

 untreated eggs less than one per cent, reached this stage. Eggs 

 similarly treated with solutions containing a higher proportion 

 of ether (0.75, 0.6, and 0.45 vol. per cent.) showed no improve- 

 ment over the control. In another series eggs exposed for 3 h. 

 45 m. to o.55ra NaCl containing o.i per cent, chloral hydrate 

 gave considerably more blastulse than the control eggs. 



It is to be noted that the improvement in the developmental 

 power of these abnormal or resistant eggs was produced only 

 by the pure salt solution or by solutions with a low concentration 

 of anaesthetic. The concentration of ether most favorable for 

 retarding the cytolytic action of 0.55?;? NaCl is considerably 

 higher from 0.5 to 0.6 vol. per cent. 1 The present effect, how- 

 ever, is not due to a simple prevention of cytolysis; the improve- 

 ment over eggs left in sea-water, none of which undergo cytolysis 

 within the time of exposure, cannot thu> U explained. The effect 

 is different from a simply protective action; and since it seemed 

 to be favored by weak solutions of ether, the experiment was 

 tried of exposing a batch of similarly abnormal eggs to sea-water 

 containing 0.3 vol. per cent, rtlu T. After three hours the eggs 

 were returned to normal sea-water and fertilized. Next day 

 it was found that the great majority of mature eggs had formed 



i Cf. R. S. Lillie, loc. cit., p. 6. 



