ISYMXOSI'OKAXGIUM. 



387 



may be as long as 10 in.iu. and are In-lit like a hum ( Fi-. l' 1 '.> i. 

 A similar case is described by I'.arday 1 in which tin- peridia 

 of aecidia <>n /,'//"///////.< ilii/mrim were Very Ion-- if produced 

 in dry weather, but short it' in moist weather. 2 



The aecidiosiMH-i-s an- shed during the t-arly part of June. 

 and germinate at once on the bark of yum; jiini]H-r-t\\ : 

 the mycelium growing tin-net- into the spur- or branches to 

 spread and hibernate. Teleutospores whieh germinate on 

 Pomaeeae other than species of Crataegus have apparently a 

 normal mycelium, but produce pyenidia only, or aecidia with 



Kl'.. ' ' jh a >WrllilIC iMU-f'l liy ,,11 



Jiinii-r--ti.-tn ; inreni-liyiiri with large ivlNaii'l tliin walls i> inx-scnt in abnormal 

 :itity. (After Wuoriilu.) 



prridia ilil'l't-ring from those on (',-n/ti i; /tix. My OWD experiments 



on the ([tiinci- and mountain ash regularly produce pyenidia only. 

 Wakkci- ;; summari/es tin- anatomical ehaii-cs induced in 

 deformed shoots of hawthorn as follow-: cork, colleiichyma, 

 -clereiichyma, and chlorophyll are not t'onin-tl, li-nitic it imi of 

 the cells ,,(' mc'dullaiy ray- no longer take- place, and there 

 are lew intereellular spaces. [nterfascicular cambium is not 

 formed, while activity of the int rala-cieidar cambium i- -u-pemled 

 at all early period, BO that the vessels remain incompletely 

 developed. The epidermis i> iiie-ulailv formed and liable to 

 rupture. All pareiichvnialoiis cell- undergo enlaiyemt-iii in a 

 radial direction. Siaich is stored up in lar-e quantity, and 

 the formation of calcium oxalate is dimini-hed. 



-. liii, t<i/. a* 



'"On tin- lii'i-.lii-inry i't /' < 



London, iv.n. 



I |in>li;il>ly i- tli'- i -.iilaiKitiini "t tin- lun^; (M-iiili.i iilit.mn ! l.\ I 



.ni'l i|i--.-i il"-<l lis M i.'iiu- i /,'//'/,/, ,/. // it',,, ,< ; 



Pringtheii \u '-. 



