872 



SCIENCE 



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



their cause,- and nothing as to the occur- 

 rence in them of any causal organism. 



Clinically and morphologically they are 

 divided into two well-marked groups — the 

 benign tumors and the malignant tumors. 

 All of these tumors, whether benign or 

 malignant, are abnormal overgrowths (cell- 

 ular proliferations) of the normal tissues 

 of the body. Every organ and every tissue 

 in which a benign tumor has been observed 

 may also become the seat of a malignant 

 tumor. Moreover, benign tumors some- 

 times behave like or become converted into 

 malignant tumors. Often, in early stages 

 of growth it can not be foretold whether a 

 given tumor will continue benign or become 

 malignant. Benign tumors are, therefore, 

 always to be considered as a possible source 

 of danger, and their interrelations, if any, 

 with cancers can not be known until their 

 causes are known. 



As a rule, benign tumors grow slowly, 

 although often eventually they reach a very 

 large size, exceptionally weighing more than 

 the rest of the body. The cells composing 

 them approximate in form, and in size 

 (that is in maturity), the cells of the nor- 

 mal tissues. Owing apparently to their 

 slow growth, there is also a body-reaction 

 in the form of an enveloping capsule, which 

 shuts off the tumor from the surrounding 

 tissues. These tumors are called "benign" 

 because while they often cause great incon- 

 venience and sometimes death, they are re- 

 stricted, usually, to the locality where they 

 first appear. That is, they do not develop 

 destructive daughter tumors in other parts 

 of the body. 



On the contrary, the cancers, or malig- 



2 Dass das Dunkel auf diesem Gebiete noch 

 nicht erhellt, des Eiltsels Losung noch nieht ge- 

 funden, das zeigt die noch stetig zunehmende 

 Fehde der Streiter auf diesem Felde. Hie embryo- 

 naler Keim, hie parasitilrer Ursprung, hie Meta- 

 plasie, hie Anaplasie, hie Anarohie, so lauten die 

 Sehlagworte der Autoren (Wilms). 



nant tumors, with a few exceptions, pro- 

 duce daughter tumors freely (often in vital 

 organs), grow rapidly, are destitute of a 

 restraining capsule, i. e., become invasive, 

 and are composed of cells, which, while 

 showing all grades of transition, are often 

 much smaller and more embryonic in their 

 appearance than cells of the tissue from 

 which they have originated, and are then 

 most malignant. These immature cells are 

 readily distinguished, however, from nor- 

 mal embryonic cells both by their disturbed 

 polarity and by their reaction to stains. In 

 other words, they are not genuine em- 

 bryonic tissue, because they do not possess 

 either the full structure or the entire capa- 

 bility of embryonic tissue. These cancer 

 cells proliferate freely, sometimes with 

 astonishing rapidity, invade and destroy 

 normal tissues, and in various ways act like 

 a foreign organism, that is, they behave in 

 the manner of a parasite, although they are 

 a part of the body. 



Without including all of the forms 

 known, or going into a swamping multipli- 

 city of details, I may say that the cancers, 

 or malignant tumors, may be subdivided 

 into four principal groups: (1) The sar- 

 comas, which are malignant fleshy prolif- 

 erations of the various types of connective 

 tissue; (2) the cancers proper, or car- 

 cinomas (including the epitheliomas) which 

 are destructive (eroding) proliferations of 

 the epithelium of the skin, mucous mem- 

 brane, and glandular tissues generally; (3) 

 the so-called mixed tumors containing pro- 

 liferating elements from two germ layers, 

 e. g., the chondro-sarcomas composed of 

 proliferating cartilage and connective 

 tissue, the adeno-sarcomas composed of 

 glandular tissue and connective tissue, etc. ; 

 and (4) the embryonal teratomas which, in 

 addition to the cancerous element that is 

 often a sarcoma, contain teratoid elements 

 representing all three germ layers — young 



