CHITCHAT UPON PHILADELPHIA FASHIONS for THE JUVENILES. Taking always as our motto that comfort and simplicity are the first principles of dress for children, we have, like a careful mother, to consider the spring outfit of the little ones, a task which many mothers dread, because they have not the tact to manage it rightly. In the first place, comfort cannot be insured without cleanliness, another of our previous axioms, and here, as in an infant's wardrobe, it is best to choose plenty, rather than fineness or elaboration, if both are not to be had, particularly in the matter of underclothing, which would form a separate chapter by itself. For a little girl just emerging from babyhood, the change is almost insensible; but very few mothers know what to do with a boy under similar circumstances. The present styles are more available than the little close cloth suit of jacket and trousers, so long in fashion, transforming the little urchin into the semblance of a monkey in his hand-organ costume. All mothers have reason to bless the invention, or rather the revival of sacques--for the prettiest, and at the same time most comfortable and convenient summer dress we can recommend for boys from two years old to five, is a loose sacque, girt, by a belt, over white linen jean drawers or "pataloons," as the young gentlemen will be apt to call them. We prefer the sack buttoning on the shoulder, with short sleeves, and rather full in the skirt, reaching a little above the knee. It may be made of any material--for spring, cashmere or mousseline de laine, plain colors or small plaids--brown Holland, with an edging of linen bobbin sewed on flat in two or three rows, as the weather grows milder, and finally, for summer heats, cambric in solid colors, as blue, buff, pink, or green, also very prettily finished by rows of bobbin or coronation braid. Needlework scalloping is also a suitable finish. Nothing could be more simple or inexpensive. Plaid ginghams might also be made up to look well, with pearl, linen, or porcelain buttons on the shoulders. There are porcelain buttons, as most of our readers know, with edges of different shades, pink, purple, etc., that will match nicely. The thin sacques might be low in the neck, with short sleeves; for a thicker material, as cashmere de bege, or mousseline, they should be high in the throat, with a narrow cambric ruffle or edge basted in the neck.