DEVELOPMENT OF EGGS OF ARBACIA AM) CH.ETOP1I-.UI-. 279 



the mixture brought to the boiling point. The solution was then 

 cooled to laboratory temperature, filtered, and used at once. 



The early development of the eggs used in thi- experiment was 

 normal, although slightly delayed. After twenty hours ciliated 

 larva- were present in great number in the -olmion. but they 

 were moving feebly and beginning to -how degenerative chan. 

 Prepared material showed that tyrosin had retarded the develop- 

 ment of the eggs but produced no abnormalities, The-c iv-ults 

 agree with those obtained by Mathcws in a similar experiment. 



Glutamic Acid (C&HbNOj. Various solution- of thi- -ub-tance 

 (i, o, i\, an d a'o P cr cent.) were used on the e - ..I ' . 1 and 



all of them proved to be injurious from the lie-inning of the experi- 

 ment. The eggs placed in the stronger solution- \\ and ' _. per 

 cent.) were killed at once. A few of the eggs subjected to tin- 

 action of the j 1 ,, per cent, solution began to -< in .1 normal 

 manner, but none of them developed beyond the earl\ stages "I" 

 segmentation. The eggs in the ^ (t - per cent, solution continued 

 to live for some time, but their development \\a- \ei\ -n-.itly 

 irded and stopped entirely when the gust nil ige \\a- 

 hed. Preparations of these eggs showed that the <!" 

 the glutamic acid was to check development, not t<> produce 

 nmi-ual types of larva?. 



Aspartic Add (CA\ 7 \(^). This sub-tame ha- a more dele- 

 terious action on the eggs of arbacia than ha- glutamic acid. 

 All of the eggs placed in a i per cent, solution and in a ^ per cent. 

 -olution were killed at once; those subjected t<> the action of a 

 ,',, per cent, solution did not develop beyond the j-cell \ 



-olution of the strength of ^ per cent, aliened a con-iderablc 

 number of the eggs to develop to the bla-iula stage, but -e- menta- 

 tion was \ - er\' irregular anel much -lo\\er than that of the . 

 in the control culture. 



Preparations of various lot- of eggs that had been treated 

 \\ith aspartic acid solution- -h<>\\ed abnormal condition- not 

 found in any of the Arhncin eggs subjected to the action of other 

 amido-acids. Most of th' that had been subjected to the 



at lion of a -^Q- per cent, -olution of a-partic acid for four hours 

 before fixation were found to be -till unsegmented, and main of 

 them had been entered by several -perinato/o.i. ( )nl\ one -perm- 



