Vol. XXII. . April, 1912. No. j 



BIOLOGICAL BULLETIN 



THE EFFECTS OF SOME AMIDO-ACIDS OX THE 



DEVELOPMENT OF THE EGGS OF ARBACIA 



AND OF CH/ETOPTERUS. 



HKI.KN DEAN KING. 

 THE WISTAR INSTITUTE OF ANATOMY AND BIOLOGY. 



hi i<>(>9, Mathews published a short account of sonic e\peri- 

 mi-nts which he made to ascertain the effects of variou- amido- 

 .11 ids on the development of the eggs of Arbacia. Tin- re-nlts of 

 these experiments have considerable theoretical inteiv-t. -ince 

 i In -\ -eem to show that the course of embryonic development 

 ( .in 1>< determined, to a greater or a less extent, by tin --e pn>dnci- 

 <>l pn>iein digestion. 



\\liilc I was working in the Marine Biological I.al>oraii>ry at 



\\ 1- llcli, Mass., in the summer of 1909, Dr. Mathcu- kindly 



Inrni-lied me \\ iih a number of amido-acids in onlrr th.it I mi^ln 

 n-pi-.n .tml c\teiid his experiments and make a drt.iilrd >tml\-ol 

 the diih ifin types of larvae that might be obtained. A~.ii -. nuil 

 \\-nili \\liiK' to determine whether amido-acids .m .iltcr the 

 course "t 1- \rli>pment in various kinds of eggs or \\lirtlirr tlu-\- 

 li.i\c a -pi i ilic action on the eggs of Arbacia, tin- tApriiiiifiii- 

 \\t-rc i ,111 ird U-vond the limits original ly intended and \\cn- ni.id<- 

 \\ith tin' eggs of an annelid, Chatopterns pcr^uncntaceits, .1- \\cll 

 .1- \\iih ilu- * ^-- of the sea-urchin, Arbacia pioictiildtd. 



In addition to cystin, leucin and tyrosin, the thn amido-.u -id- 

 which Mat lieu- used in his experiments, both kind- >t e;^-- \\ 

 subjected to the action of glutamic acid, asjianii- acid, a -pa rapine. 

 ^l\c(noll and alanin. In each series of experiment- eggs from 

 two or more females were thoroughly mixed and then artificially 

 lenili/ed in -ea-\\ater. As soon as the polar bodie- had been 



273 



