strongly bending its tail inwardly towards its head. In a few minutes the whole of the tail or abdomen is outside of the old shell, and the two may he seen side by side. Then the exuviation of the front half of the lobster goes on, all at once, legs and head-appendages and body together, and the last portions but one seen of the creature in its fresh covering are the tips of the large anterior limbs, which, as I have said before, are for a few minutes a little misshapen. Last of all appear the longer tentacles. During this process, which from first to last takes up about a quarter of an hour, the lower edges of the cephalo-thorax become a little separated from each other, laterally, to the extent of about one inch in a large specimen, and this appears to be for the purpose of allowing more room below than would otherwise be possible for the extrication of the limbs. To this end, therefore, and in my opinion for no other, does the straight longitudinal furrow, and its membrane below, constitute a kind of hinge or joint. As soon as the old shell is quite detached, and the animal is in its normal position, and has rested for a few minutes, it pushes the cast 6hell over the edge of the earthwork of sand and shingle, outside the den. Sometimes the lobster buries its old coat ; but in any case this rough usage of it has a tendency to break the very tender membrane at the hinge, and usually it is found torn, and the cephalo-thorax in two. But when an observer, quickly after exuviation, very carefully removes it out of the water, it will be found quite whole, and if the shell be immediately set-up on a board it may dry without separation ; but usually even then it begins to split, unless such splitting be arrested by gumming narrow strips of thin paper outside, across the joint, at intervals. However, I think I have said enough to show that no part whatever of the lobster is necessarily ruptured, save the membrane transversely where the cephalo-thorax and abdomen join, and that absolutely the whole of the interior animal comes out through the orifice thus formed ; also that no breakage or splitting of the shell occurs anywhere else, the longitudinal split of the upper fore-part of the shell being merely an after-accident. After solidification, in three or four days, or within one week, the shell or animal never increases till the next exuviation."
Truffles. — Most people are familiar with the appearance and taste of truffles, but few probably know anything about their organisation and reproduction. The subject is a very curious one; and although more suited perhaps to a botanical journal, it may be discussed not inappropriately in a magazine of Natural History. A French writer says ('Revue Encycl.' xxxv. 794):—"The truffle, Tuber cibarium, is a vegetable entirely destitute of leafy appendages and of roots ; it is nothing more than a rounded subterraneous mass, absorbing nourishment upon every point of its surface,
