In some of the reviews of the former volume some adverse criticism was given on account of the absence of microscopic findings confirming the diagnosis of the cases reported. I explained at the time that any attempt to excise portions of tissue for such study would at once endanger the patient and imperil the success of treatment, by giving occasion to metastases, from the opening of blood vessels and lymphatics. This matter is treated of more fully in the present lectures. It is to be remembered that the vast majority of operations for cancer are undertaken upon a purely clinical diagnosis, and it may be undeniably stated that not one half of them are confirmed subsequently by competent microscopic evidence, except, of course, in properly equipped hospitals. In some of the cases now presented pathological proof has been presented, while in every one the clinical signs were so unmistakable that no one could possibly doubt the correctness of the diagnosis. A number of reviewers of the former volume regretted that fuller and more definite statements had not been made in regard to the exact diet and mode of treatment employed in the cases reported. I had explained that it was very difficult to develop all this in the brief compass of a few lectures; indeed I may now say that it would take many times the space and time which could be given to it to develop fully all the possibilities and requirements of a dietary and medicinal treatment in every case. The object rather was to inculcate the basic idea of the true causation of cancer, leaving it to the practitioners present to carry out the measures calculated to reach the desired end. In order to make matters very clear I may occasionally have repeated some things said in the former lectures, and some repetition may be found in these successive lectures; but this will be pardoned when it is considered how necessary repetition often is in order to establish correctly a new thought. The cases were given as illustrations of what could be accomplished along the lines indicated.