TENSION PHENOMENA OF L1VINC, KLI.MENTS. 155 



This is made more striking by the fact, mentioned first by 

 Loci), that haimolytic agents are effective in artificial partheno- 

 ui -nesis. R. Lillio observed that pure solutions of sodium salts 

 caused the egg to divide, the order of effectiyene-s of unions being 

 'Br<ClO 3 <XO 3 <CXS<I. He also found that these salts 

 could !>e inhibited by others (CaCl;, MgCl 2 ), as i- characteristic 

 of the antagonistic effects of salts in physiological phenomena, 

 and tin- pr.-i ipitation of colloids. 



1 found that the sea urchin's egg contains fatty sul Mance-, and 

 ielati\el\ large amounts of lecithin probably in combination with 

 pioirid-.. I found that Toxopneustes eggs freed from tin.- jclly- 

 likc ci.\crin^s, contained about 10 per cent. lecithin 'alcohol 

 extract p|it. with acetone) and about 2 per cent, of an extract 

 -olul'le in alcohol or acetone and containing rosette-. <>t tat -like 

 taU. This extract blackened strongly with o-mic tein>\ide 

 and -lter\e-ced on adding dry Xa-carbonate in \\atcr, Hun 

 emul-ilied. probably it contained unsaturated fatt> aciil. 



\<.i<ling to a private communication by Mathews, tin- 

 of i he -taiii-h contains lecithin and an unsaturated tatty acid, 

 but no ( ho]rMerin. In this last characteristic ii diller- markedly 

 from the eiAthrocyte. There is no way of determining \\hether 

 tin -i -ub-.t.inces enter into the composition of the plasma 

 membrane, but the facts are presented in order to indicate the 

 pi '--ibiliiies. 



\\ e haM'seeii that the exit of haemoglobin i> probably nm due 

 t. in. i, MM. I permeability to this substance. It is po--ible ihat 

 the same i- true of echinochrome. I found that the echiuochroine 

 in the e;cu -hows a continuous spectrum, when-a- that extra< led 

 in \arioii- ways shows characteristic band^. It ma\ po-^iMy 

 In held b\ chemical combination in the e. 



llo\\-\er I found. other evidence for increase in permeability of 

 the sea urchin's egg coincident with be^innin^ d-\< lopment :' 



t. 1 eiiili/cd eggs are caused to shrink more quickly than un- 

 t\-i tili/i .1 eggs, with isotonic sugar solution. Presumably the 

 fertili/ed euv;s are more permeable to the substances exerting 

 the internal osmotic pressure. 



j. Tin- electric conductivity of the euy increases about ' \ \\hen 



\1, Cl. -in Ion. Attifr. Jour. Physiol., 1910. XX\ II., 240. 



