PHOTOTACTIC REACTIONS IN THK MAY-FLY. 



267 



TABLF I. 



In tnrlhcr lAprrinifiit- .in .ipp.ir.it u- essentiall) th<- -.inn- as 

 ih.it UM-d 1>\ Strasl :u hi- uork on rrnti.\t<i u.i- ciii|il<'\ .-d. 



It con-i-trtl <!' .1 |>ri-m i.l' .1 -ihilii>M <>l Imli.i ink |)l.uc<l over .1 

 L.III; glass tniU^ll tin- sides .unl lM,|t(,ni of \\llicll \\riv IM 

 over \\ith \\hiii- ]I.I|HT I ' n spe< inn n- \\rn- ]il.u'i-il iii tin- r 

 of tin- trough uml.T tin- thin portion of tin- pri-ni, .uul uhni 

 I'.iirU i|iiirt tin- li^ht \\.i- ri'lln tnl ] M T] .mi i icul.irly through tin- 

 pri-in i;i\iii^ .t perl .i<l.ition in tin.- intniMtv of li-ht troin 



one mil of the troii'Ji t. tin- otluT. Th rev <>f tin- specimens 

 immrili.itrly -\\.ini to\\.irl tin- 1. irk i-ml of tin- trough ; four otln-r 

 fo|lo\\cil \\ithin h.ill .i niinntr; and the rfin.iinin- three collected 

 into .1 -ioup n-in. lining th.it \\.tv for ,i lV\v ininutr> \\lx-n tlu-y 



