One sometimes encounters an intense zeal which causes one social worker to try to do her own, and everyone else’s work as well; or even worse than this, to neglect her own work in order to do that of another person. All social workers should learn where to stop—where to transfer the case to someone else better fitted to deal with another phase of it. We sometimes hesitate to call in other agencies, because they do not recognize their boundaries. Co-operation should be substituted for rivalry and interference; when this is brought about, petty bickerings and jealousies among the social agencies will cease. To become an effective co-operator, instead of a critical interferer, the public health nurse must familiarize herself with all the agencies in the wide field of social service. She should try to understand the object and method of their work, and to know where her own work interlocks with theirs. In a way, they are all interdependent, one upon the other, and have the same object in view—to relieve distress and raise the sum total of human happiness. Whether their work is effective or superficial is not our concern. The nurse should understand what each of them has to offer, and by picking here and there among them, secure valuable assistance for the families under her charge. She can thus reinforce her own efforts, and supplement her own work in behalf of their well-being and security. Since nurses come in almost daily contact with the Charity Organization Societies it should be part of their duties to attend the local district meetings of these associations, for during the discussions which take place, the nurses are able to give most helpful information concerning their own cases, while in regard to other cases, not complicated by a communicable disease, they learn much as to the methods and theory of relief-giving. For this reason, these district meetings are useful to both nurse and agent alike; the interchange of opinion enlarges the outlook of both workers, and each gains an insight into the difficulties of the other’s work. This interest and understanding promotes good feeling, tolerance, and personal friendliness—the basis of successful team work.