SCIENCE 



[N. S. Vol. XLIII. No. 1121 



geranium, but in this connection I invite 

 your attention only to a small portion of 

 its surface (teratoid part) where strange 

 phenomena are in progress, quite like what 

 often occurs in the epithelium of human 

 teratoids. Here is a compact, small, surface 

 tumor showing subepidermal erosion, an ef- 

 fort on the part of the plant to protect itself. 

 Its deeper tissues fuse into those of the epi- 

 dermis in such a way as to suggest that 

 they have originated from the latter, i. e., 

 there are no epidermal and subepidermal 

 differences, although these differences are 

 conspicuous in the normal plant and also in 

 other parts of the teratoma. In this late 

 stage of development it is impossible to tell 

 what may have been the origin of these 

 queer tumors, but what appear to be much 

 earlier stages of the tumor are visible in 

 several places, especially on their margins. 

 and these places exhibit, or seem to exhibit, 

 all stages of transition between the normal 

 one-layered faint-staining columnar epi- 

 dermis (equivalent to an epithelium), and 

 a several-layered, large nucleate, loosely ar- 

 ranged, deep-staining tissue, the cells of 

 which are rounded or angular and have 

 lost their polarity, that is, their orderly 

 relation to their fellows. Now this is ex- 

 actly what takes place in early stages of 

 carcinoma. For instance, below the one- 

 layered epithelium in glandular tissues of 

 the breast, of the stomach, etc., irregularly 

 placed, large, deep-staining, rapidly pro- 

 liferating cells make their appearance as 

 shown on the next slide, which is from a 

 cancer of the lung. This kind of prolifera- 

 tion is recognized as the beginning of a 

 malignant tumor, and surgeons base their 

 operations on its presence or absence. If, 

 in the breast, let us say, this displacement 

 of cells is present, then the surgeon does a 

 major operation, but if it is not present, 

 then he is content with having removed 

 only the local nodule. These surface tu- 



mors on the geranium were accidental dis- 

 coveries, but I have now begun a systematic 

 inoculation of the skins of plants to see 

 what I can get. 



I have what I believe to be the same phe- 

 nomenon (a mixed tumor) on tobacco. 

 This tumor I produced out of young cortex 

 in 1907, but it has been properly stained 

 and critically studied only recently. Its 

 outer part consists of blastomous cells quite 

 different in shape and staining capacity 

 from the cells of its inner part. The outer 

 cells are more or less compact and angular 

 and the protoplasmic contents stains uni- 

 formly. The inner cells are round, more 

 loosely arranged and stain like the ordi- 

 nary sarcoma cells of this tumor. In con- 

 nection with the last slide I would also call 

 special attention to the evidence it shows 

 of the appositional transformation of nor- 

 mal cells into cancer cells (atypical blas- 

 tomous cells). I refer to the band of tissue 

 lying between the normal cortex on the 

 right (out of which the tumor has devel- 

 oped), and the fine-celled hyperplasia on 

 the left. These 10 or 12 rows of cells, 

 bordering the tumor, have the same ar- 

 rangement as the tumor cells and stain 

 deeply like those of the tumor, but are sev- 

 eral times as large. Occasionally an un- 

 changed cortex cell is buried in their midst. 

 They are, I believe, a transition from the 

 normal tissue into cancerous tissue.'' The 

 same phenomenon has been seen in human 

 cancers by several good observers and there 

 can be no doubt as to its occurrence. 



Finally, from shallow bacterial inocula- 

 tions done on the glands of Bicinus last 

 winter I have also obtained what appears 

 to me to be satisfactory evidence of gland- 

 ular proliferations, i. e., rapid multiplica- 

 tion of the surface layer of cells with loss 

 of form and polarity and entrance into the 



'' See The Journal of Cancer Mesearch, April, 

 1916, PI. XXIII., Fig. 78. 



