Figure 73. 

 fp, 187) 



Figure 74. 

 (p. 199) 



Figure 7g. 

 (p. 200) 



Figure ..76,. 

 (p. E02) 



Figure 77. 

 (p. EOS) 



Figure 78 

 fp. 205) 



Figttr? 79. 

 (p. 208)' 



Figure 90 < 

 (p. 212) 



Figure 81. 

 f; 214) 



X. 



Catalpa « Tissue resambling wound cork from 

 branch. (Place of rupture of bud) . 

 (Original) 



Vaccinium Yitis Idaea . a, cross-section 



through a leaf, the swelling of v/hich 

 has "been induced by infection of its 

 central portion v^th Exobasidlum Vsc- 

 cinii. b, part of a leaf (highly magni- 

 fied) ^ich illustrates the difference 

 between normal tissue (at the left) and 

 the diseased ( at the right) . Ilhe hyphae 

 of the fungus are not shown in the 

 drawing. (After Woronin) . 



Crataegus ; Oxyacantha « Cross-section through 

 a leaf infected with Aphj.s Oxyacanthae. 

 (Original) 



Pyrus Malus . A branch infected for several 

 years by the blood louse, bearing 

 clustered "canker" structures. (After 

 Prillieusj) . 



Gymnosporan^ium junipe ri num . Tangential long- 

 itudinal section through the wood gall» 

 Only one abnormally broadened medullary 

 ray (atove at the left) has been drawn, 

 the others are o^jly indicated by white 

 fields. (After WGrnle) . 



Longitudinal section through the gall of the 

 blood louse, ( Schiaopeta^a lanigera ^ . In 

 a, the cells are stiil arranged in recog- 

 nizable longitudinal raws; their walls 

 are thickened.. In b, thin-walled gall 

 parenchyma without recognizable, longi- 

 tudinal rows; two parenchymatic tracheids. 

 (After Prillieux) . 



FaguB., longitudinal section through the gall 

 of the beech wood louse ( Chermes Fagl) 

 Above, cork oelXs (k) , below normal oast 

 "tissue (b) . In the middle abuiodaat gall 

 parenchyma (p) in which are enclosed two 

 groups of stone cells (sk) . IThe prosen- 

 chymatic elements of the bast have been 

 pushed aside in curves and misplaced by 

 the increasing bark parenchyma. {After 

 E. Hartig) . 



Cross-section through the gall of S ynchytriu m . 

 fe ^ilificum. the nutritive cell in the 

 middle. (Original) . 



Production of sac gall, digramaatically re- 

 produced. (Original) . 



