l-URTHl!R RhSHARCHl.S IN DiSl-ASI-S OF PLANTS 529 



subject. The third volume was T. 1^. M.iUorv's I'l/naplcs of Path- 

 ologic Histology,'* and by July 20 he entered in his diary an impor- 

 tant observation: 



I-inislicd rcadin.c: the middle 96 p.is;cs of [G]. Hauscr's A/f Cylinder- 

 epithel-Carcitiom lies Migcns und dcs Dickdarws, the most important part 

 for my purposes, the first part being chiefly history and classification and 

 the last part a history of cases. It impresses me as a thoroughly good piece 

 of work based on original research with a full knowledge of the literature. 

 He is opposed to the" doctrine of parasites as a cause but I can answer all 

 of his objections. Striking is the resemblance of crown gall to cancer in 

 its conversion of normal cells into tumor cells by apposition. He says in 

 tumors big and little, ulcerated or not, there is a periferal conversion of 

 normal gland cells into cancer cells all stages of which can be seen under 

 the microscope. I must copy out some of his remarks. It would be 

 interesting to write a commentary on his discussion of cause of cancer, 

 entitled 50 years after. 



Three days later his diary read: '" Two hot sticky days. 96° F. 

 in the hothouse where I made inoculations of crown gall on 

 tobacco (Res. Daisy and Hop.) I wish to get tumors duplicating 

 one of several years ago showing conversion of normal cells into 

 tumor cells by apposition." In a pencil notation, at the foot of 

 the page, obviously written some while later, but undated, appears: 

 "I got many such which have since been cut in serial sections 

 stained, studied and photomicrographed." 



On September 10 he examined under the microscope " a box 

 of stained crown gall sections from tumor (3 weeks old) on young 

 tobacco stem cortex, the inoculation being from Resistant Daisy 

 Strain. They show," he wrote in his diary, " invasion of the 

 phloem and wood and distinct conversion of cortex cells by apposi- 

 tion. I have marked certain ones to photomicrograph." Late in 

 October he noted also: 



In some of my Ricinus inoculations into vicinity of leaf glands I have 

 found superb invasion of the cortex by crown gall cells and will pick out 

 some for photomicrographs. . . . Working over the Ricinus slides. Some 

 show very beautiful clumps of crown gall cells between much larger and 



" In Dr. Smith's scientific library at the time of his death in 1927 were: E. Ziegler's 

 General Pathology, N. Y., Wm. Wood, 1918 (translated from llth revised German 

 edition, Jena, Fischer, 1905), and, F. Delafield and T. M. Pruddcn, A text book of 

 pathology, Ed. 13, N. Y., Wood, 1925. His diary, however, reads: " Ziefiler by 

 Warthin, Delafield & Prudden by F. C. Wood, and Mallory (Pathologic Histology)." 

 A pencil-written notation says of the Delafield & Prudden text, " revised by " F. C. 

 Wood. 



