Now although the Humming-birds, or living sunbeams, are all of them small birds, yet they are not all of the same size, and some are quite big compared to others, just as a peacock butterfly is quite big, compared to a tiny blue one, whilst even the tiny little blue one may be big compared to some very small moths. Then, again, their beaks are of all kinds of different shapes and lengths. Some are quite straight, whilst others are bent like a sabre or even a sickle, and one Humming-bird has his so very much bent indeed, that it looks like half of a black ring or bracelet or something else that is quite round. As for length, some are shorter than a quite short pin, whilst others are longer than a very long darning-needle. [Illustration: RACQUET-TAILED HUMMING-BIRD] Of course there is a reason for the beaks of Humming-birds being so different, and the reason is that they have to go into different flowers, and must fit into them as a finger fits into a fingerstall or a periwinkle into its shell. If the part of the flower that holds the nectar is straight, then the beak of the Humming-bird that feeds on the nectar of that flower must be straight too, but if it is curved, then, of course, the beak must be curved, or else how could it be pushed into it? And if the nectary of any flower (for that is what the place that the nectar is in is called) were shaped like a corkscrew, then the beak of the Humming-bird that sucked out the nectar from _that_ flower would have to be shaped like a corkscrew too. But there are no flowers shaped like that, and so there are no Humming-birds with corkscrew beaks, like the tail of a periwinkle. But there _is_ a flower that has its nectary, or honey-tube, bent round into almost a half circle, and it is just that one Humming-bird that has its beak bent in the same way, that sips the nectar from that flower. No other one is able to do it, and there is no other flower that that Humming-bird can sip the nectar from.