Furthermore, in some parishes, the natural growth of the population was very rapid. In Islington, for instance, the Medical Officer of Health wrote:-- "The Life Balance Sheet of your parish for 1875 shows that your losses and gains leave you 4,376 lives to the good, or in other words 4,656 deaths and 9,032 births have been registered in the parish of St. Mary, Islington." And the Medical Officer of Health for St. Marylebone wrote (1877):-- "If we compare the annual number of births with the deaths, we shall find that every year some 1,200 or 1,500 more persons are born in the parish than die in it; and what, it may be asked, becomes of the surplus population? The only answer is, that it migrates; it could not remain in the parish for the simple reason that there is no room, all available spaces in St. Marylebone have long been built upon, and the houses occupied, many of them crowded." To the migration rendered necessary by the natural growth of the population, and by the diminishing number of houses in the central parts, was added the ceaseless stream of fresh immigrants into London. These vast numbers had to find house accommodation somewhere, and they found it, in their tens of thousands, in various parts of the less central portions of the metropolis. In Kensington, for instance, the Medical Officer of Health stated (1871) that the larger portion of the increase of nearly 41,000 in the ten years was due to immigration. The Medical Officer of Health for Fulham drew a graphic picture of this inrush of humanity. "The steady growth of London westward has thrown among us a vast and teeming population of the working classes, as well as those of more well-to-do condition, and for the housing of the former many blocks of wretched and most miserably constructed dwellings continue to be erected with the most utter disregard for drainage or other sanitary appliances now so essential. That part of Fulham, once open fields, is still being rapidly covered with streets and houses of this character, and many open spots in Hammersmith are being filled in the same way. Our healthy neighbourhood may thus be made ere long a land of sickness and disease unless some check is given to such speculative buildings. Our natural advantage with all our care will not avail us against such utter recklessness." The increase of 21,000 in Paddington drew from the Medical Officer of Health the query-- "... Whether any and what steps should be taken to prevent the wholesale influx of a colossus of pauperism with the consequent burdens of poverty and sickness." It had already driven the people underground for shelter, for in 1871 he described how--