THE GRAPE PHYLLOXERA IN CALIFORNIA. 21 
their wood growth than do healthy ones. Such grapes mature, how- 
ever, without attaining a good size or their normal saccharine con- 
HSISPSPSH 
//// S//PSPS//SPS 
SPPS/-/SSWHSSSS 
sP S S S S P S S P S H 
S S S S I S S S S S >' S S S- S S H 
SSHSSPSSI S P H S P S S 
S I S S S S S S S I U I P S P S M I S 
J> S P " S P S S ID S S S U 
s s s s s s Sip sisspic/ssps u 
I 
SPSS suss I S S S S S P S I IS! 
S 
$ S HP S S I u I s S S S P I s s p p s P 
P 
P H H S H P S S S I S S IIS S 
HHSSPSSISSISISPI I U S S S 
P 
P P P S S U U I III I I • D S I S S S S 
H 
P P S I / D I I • • D • P U D D V I S 
S 
P S S I S I U • • • • • • P i s 
s S S S S II u •••••••• u U . / S P 
H 
HPIPIUDD*****D*PPDISP 
S P I I IUU**U*****DDP IPS 
p p p iii • d m ••• / / / s 
P P S S 1 1 1 I I0D****l//7SPS 
PHSPIDIIUIU + * + DIIPPHH 
P S P S S b r I UIUUD + IISSPSH 
H S H III I * V V I V P S H H 
HPPUIISIIUIUVUIIIPHHH 
P P I III I S U • • • P / S H H H H H 
p S P P S S I I 1UI%IPSHHHSH 
II S P P U U S H S H 
H Hcalthy D P S P V I I U S P S P S H H 
P Plight infestation IPIPISIIHHHSH 
I Infested SPSHHPSHHSH 
U UNHEALTHY S S P P S S 
D Dying P S S P P S H 
# DEM H 
Fig. 3. — Phylloxera "spot" in Zinfandel vineyard, charted in 1915. Same "spot" 
as shown in figure 2. (For description see text.) 
tent. Stunted vines produce leaves of a more uniform size than 
healthy vines, and because the internodes of the canes are shorter, 
the leaves appear more closely grouped, giving the " cabbage-head " 
