98 E. G. SPAULDING. 



the attainment of that ideal. To attempt to do this states ac- 

 cordingly the purpose of this paper. 



The second genetic element was the desire to get such a uni- 

 tary view as at least a preliminary to and if possible a justifica- 

 tion of the attempt to initiate segmentation by new methods, 

 viz., by the application of the electrical current to the unfertilized 

 eggs of the starfish, and although these experiments were unsuc- 

 cessful, the theory, although based on the experimental work of 

 others, is offered for what it may be worth as an endeavor to 

 gain an end, the value of which in itself will not be denied. 



i. EXPERIMENTAL DATA. 



A brief recapitulation of the results already obtained by arti- 

 ficial parthenogenetic methods may, as a preliminary to subse- 

 quent discussion, be pardoned. 



In the starfish egg parthenogenesis may be produced by : (i) 

 the use of HC1 ; l (2) increasing the osmotic pressure of the 

 surrounding medium ; 2 (3) by lowering the temperature ; 3 (4) by 

 mechanical agitation. 4 By the first method it is held that the 

 "parthenogenesis of Asterias eggs is to be produced by means of 

 specific (hydrogen) ions," at least this is the interpretation of the fact 

 that 100 c.c. of sea water plus 3-5 c.c. N/io HC1 acting for 

 from 3 to 20 minutes on the eggs, which are then removed, brings 

 about the desired result. 5 In the case of the second method, 6 

 although the results are stated somewhat ambiguously, the maxi- 

 mum number of parthenogenetic eggs seems to have been se- 

 cured by using 15 c.c. of 2*4 N KG + 85 c.c. of sea water at 

 about 23 C. for 15 minutes, then transferring. As for the third, 

 " e gg s f Asterias may be made to develop parthenogenetically 

 by exposing them for a definite length of time to a temperature 

 of i -/ C., in sea water, and then raising the temperature." 

 As an interpretation of this, we find it stated that "the produc- 



1 Loeb, Fischer u. Neilson, Archiv fiir die geschichlliche Physiologie, Bd. 87, 1901. 

 2 Greeley, A. W., BIOLOGICAL BULLETIN, IV., 3, Feb., 1903, says that Neilson 

 found this method successful. 



3 Greeley, A. W., Am. Jour, of Physiologv, VI., 1902, p. 296. 



4 Mathews, A. P., Am. Jour, of Physiology, VI., II. 



5 Loeb, Fischer u. Neilson, loc. cit. 



6 Greeley, loc. cit. 



