74 A. J. GOLDFARB. 



H. V. Wilson ('n), Miiller ('u), and others demonstrated that 

 somatic cells could also be fused. 



Several investigators have repeated Driesch's experiments 

 with the echinoderms found on this side of the Atlantic but 

 without success. By slightly modifying Driesch's method, 

 I finally succeeded in agglutinating and fusing the eggs of 

 Arbacia punctulata at Woods Hole, Mass., in relatively large 

 numbers, ten to forty in every hundred. 



In this paper, I propose to give a detailed account of the 

 method used in successfully fusing Arbacia eggs, to state briefly 

 the effect of the treatment upon normal development, and to 

 describe some of the agglutinated and fused embryos and larvae. 

 Since Driesch has given so full, so clear and accurate an account 

 of fused larvae, I will in this paper emphasize the earlier develop- 

 mental stages and state but briefly in how far the Arbacia larvae 

 are like or unlike the European fusions described by Driesch. 



METHOD USED TO AGGLUTINATE EGGS. 



The eggs of Arbacia punctulata were shaken violently two to 

 three minutes after fertilization so as to remove their fertili- 

 zation membranes. They were then placed in a calcium-free 

 sea water (van't Hoff formula) prepared with copper or glass 

 distilled water. To this solution four to twelve drops of 0.5 per 

 cent. NaOH were added to every 200 c.c. of the solution. The 

 eggs remained in this alkaline solution for varying periods, as a 

 rule not longer than the first cleavage. Up to this point the 

 method is the one used by Driesch, a method which failed alto- 

 gether to agglutinate the Arbacia eggs. They were then trans- 

 ferred to narrow bore tubes, about 1/8 inch inside diameter, and 

 centrifuged for three to five minutes at about 30 revolutions per 

 rrunute, and finally placed in sea water. The cultures so treated 

 later contained the agglutinated and fused embryos and larvae. 



As it seemed probable that the violence of the treatment might 

 produce atypic results, a preliminary examination was made to 

 ascertain to what extent anomalies were present in the cultures 

 and how far these were the result of the technique used. 



