No. 454-] AA'ATOAfV OF THE 



of the prominent resm cells which aiv ..ttcii inliiivU.-l\ iss^H-i- 

 ated with the cysts. 



The normal course of devcloiMncnt hu mu li -v^ls -.^ tluis 



involve an unusual slmuilus to i^mwlli and undri ^m ii cii' Min- 

 stances they may become dchnitclv assDi iatcd with mi- \^Y\\ rvrn 

 be regarded as indicatnc ot. i)alh(»loi;ical c. mdn k .ns Thus 

 Anderson (i, p. 28-29) has sliown that such ('\sis arc dctuiiU'ly 



m Abu Jiima Lndu such ciuum-.tun.. llu \ U hk 

 much larger, more distant and more numerous than in iioi nial 

 growth, but thev form well dehned tangential rows m ilic carhcr 



ot such secondary features the cvsts mamlestl\- exlubil a distinct 

 approach to that higher t\ i)e ot structure and distribution whicli 

 IS exhibited in Picea. In the tollou ing vear Aiuka-son ii. p. :i6) 

 further showed that while resm cvsts arc absent trom the nor- 

 mal wood ot //. balsiunca thev do arise under the iiitluence ot 

 the special stimulus connected with the tormation ot tumors 

 produced by the action oi . luidiiDU ilatmnni. He turthermore 

 points out that such cvsts attain their greatest de\ eloi)ment and 

 largest number in the region of greatest stimulation, /. m the 

 middle ot the tumor, decreasing above and below until they 

 eventually become pointed and finallv tlisai^pear between tour 

 tiichuds which, m then mcnstcmitu c mditi >i pi,l)iblv 

 function as epithelial cells. ' It is untortunate that the histo- 

 logical dctuls of thcsL t\-ts md then eudin^- ue not ^i\en 

 since such ficts would scixe to thi w m 1 h li^ht up n tlu uli 



there is no reason to suppose that thev differ in their essential 

 stiuctmc tumi th sc which occui m the n imd tissues t the 

 Mmc 01 othci species IhetiiLheuK d) . c lULiudt ik un 

 doubtedlv parcMU-hvma tracheids. and it is probable that turthei 

 examination would show that they ultimatelv rei)lace the lesm 



More recently leffrey (24) has contributed m impoitant 

 paper on the anatomy of Sequoia m which he bi in^;s out sev- 

 eral facts of considerable value. He shows that resm c \;,ts ma> 



