494 MAX MORSE 



under slow heat to small proportions. The whole was then treated 

 with cold ether for twenty-four hours in a flask, filtered, the fil- 

 trate treated with acetone in a separating funnel, the precipitate 

 drawn off and filtered through paper. In the meantime, the resi- 

 due from the first filtration was wrapped in heavy filter paper 

 and extracted in a Soxhlet with ether and the treatment there- 

 after was similar to that of the second amount. The precipitate 

 from the acetone was purified with absolute alcohol. A good deal 

 of difficulty was experienced in getting rid of the pigments and 

 at last this was given up, for it did not seem that luteins could 

 influence the results in the minute quantities in which they 

 appeared. By this method — that is, cold ether and hot ether to- 

 gether — one may obtain a large proportion of the lecithins present 

 in the egg. The objection is that the use of hot ether may break 

 the lecithins do^vn into stearin, or whatever fatty acid is present, 

 and in the experiments upon the eggs, it may be this which gives 

 the effect in case any effect is observed. However, in neither 

 the lecithin from the hen's yolk nor that from the gonads of Arba- 

 cia, did any positive evidence appear that the reagent exerted 

 any effect whatsoever upon the unfertilized eggs. For this reason, 

 no other method for obtaining lecithin was utilized.^ 



I am unable to convince myself that the final word has been 

 said with respect to this matter. There is doubtless some key 

 to the production of development in the unfertilized egg of such 

 forms as we have mentioned which are refractory to artificial 

 stimulation. Perhaps I have used too weak and perhaps too 

 strong stimuli, although it seems that I should have discovered 

 sonnie where amongst the various strengths and various reagents, 

 some combination that would have led to favorable results. It 

 may be, as Lillie found in the star-fish, that the eggs become highly 

 impermeable or are highly impermeable in the case of Cerebratulus 

 to the reagents and that something must be done to render the 

 permeability temporarily of lower value. But in saponin and 

 other cytolytic reagents, it seems to me we find just such a reagent ; 

 and these I have used. 



* It is interesting to note that Robertson (Journ. Biol. Chem., 12: 1) reports 

 success with a product obtained by cytolyzing sea-urchin eggs extracting with 

 water and finally precipitating with acetone, in inducing membrane formation. 



