Excerpt from A Course of Lectures on Tumors: Given Under the Aupices of the Cancer Commission of Harvard University, Founded by Caroline Brewer Croft, June 16, 1899 In a former publication' I called attention to the frequency of tumors in certain families of mice. In one family of 25 mice there were 4 primary adenocystomata of the lung. Another family was derived by the breeding together of the Offspring of a female mouse with a large adenocystoma of the lung. After 100 mice were obtained, the breeding was stopped, and the mice were then kept under observation. Of this family Of 100 mice, 89 are now dead. Definite tumors were found in 15 of these. Practically 1 mouse in 6 developed a tumor. A considerable number of these mice died while young of infectious diseases, accidental conditions, etc. Inasmuch as in the above estimate all were counted irrespective of the age attained, the proportion of those developing tumors is large. Thirteen Of these mice presented adenocystomata of the lung similar to that which was found in the mother of the family, 2 had mammary tumors in addition to lung tumors, and 1 had double ovarian tumors. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.