Yet as life advances there are peculiarities which belong to individuals and to families. One group thins as life goes on past forty; another group as surely takes on flesh; and the same traits are often inherited, and are to be regarded when the question of fattening becomes of clinical or diagnostic moment. Men, as a rule, preserve their nutritive status more equably than women. Every physician must have been struck with this. In fact, many women lose or acquire large amounts of adipose matter without any corresponding loss or gain in vigor, and this fact perhaps is related in some way to the enormous outside demands made by their peculiar physiological processes. Such gain in weight is a common accompaniment of child-bearing, while nursing in some women involves considerable gain in flesh, and in a larger number enormous falling away, and its cessation as speedy a renewal of fat. I have also found that in many women who are not perfectly well there is a notable loss of weight at every menstrual period, and a marked gain between these times. I was disappointed not to find this matter dealt with fully in Mrs. Jacobi's able essay on menstruation, nor can I discover elsewhere any observations in regard to loss or gain of weight at menstrual periods in the healthy woman. How much influence the seasons have, is not as yet well understood, but in our own climate, with its great extremes, there are some interesting facts in this connection. The upper classes are with us in summer placed in the best conditions for increase in flesh, not only because it is their season of least work, mental and physical, but also because they are then for the most part living in the country under circumstances favorable to appetite, to exercise, and to freedom from care. Owing to these fortunate facts, members of the class in question are apt to gain weight in summer, although many such persons, as I know, follow the more general rule and lose weight. But if we deal with the mass of men who are hard worked, physically, and unable to leave the towns, we shall probably find that they nearly always lose weight in hot weather. Some support is given to this idea by the following very curious facts. Very many years ago I was engaged for certain purposes in determining the weight, height, and girth of all the members of our city police force. The examination was made in April and repeated in the beginning of October. Every care was taken to avoid errors, but to my surprise I found that a large majority of the men had lost weight during the summer. The sum total of loss was enormous. As I have mislaid some of the sheets, I am unable to give it accurately, but I found that three out of every five had lessened in weight. It would be interesting to know if such a change occurs in convicts confined in penitentiaries.