10 



MASS. EXPERIMENT STATION BULLETIN 366 



u. O 





1- o 



^C O lO ■* re 



— t^ -H Cvl O O r-) 

 T^' .-' O uo O — ' t^ 



r^ •^ ■* '* U-> VC LO 



rrjioiorOCvOO — C^^CO 

 I000<~ei000ro0v0i0^<-<1 



r-T .^■' (sT cvT oT oT f-"^ oo" t^ (N -^ 



rt< •rt^ re "0 

 CN ■^ 0\ re 



On OS On O 



O O OS Os Os OS 



LOCsoOi^re-^-^sOOsio 



(rNr~-reiosO'-'— 'r^t^^ 



^_ Tj< .-^ 00 lO -* oo O re so lO so 



cT -* " " " " 



CN tN fN 



uoreOto<M-*reiO 

 - - o re re c^ rN o 

 >i fN r-j rsi CN c^ 



'^OOreOs-^Or^O 



00 LO 



reso-^Oi~-reioos 



reON'^OOt--reaO 



lO— (lO'O-^rt'OOiOoor^isoO^ 



so Os" r^ o" Jn" ■^'' so so" so Ol oo" 00 



O O. OS OS 'OS c 



t^ CN csi t^ O sO 



re O Os (M sO t^ 

 so — t^ re CN »^ 



■<* — < O O SO CN 

 t^ l^ r^ so so t^ 



.-H, Uh S < 



1 S I i I 

 O Z Q 



r:;^^< uo 



be 



2 m 



