VOL. XXII.] PHILOSOPHICAL TKANSACTIONS. 5iy 



out, one of the before-mentioned hooks will remain in the web, whereby when 

 it draws in its body, the shell wherein it is involved cannot follow ; in doing 

 which, the creature gets rid of it more readily ; and we anew discover the un- 

 speakable perfection of such a small insect, if we take a view of the mani- 

 fold and inconceivable number of the feathers and quills, which stick in the 

 body and wings of such a moth, and which by their flying and leaping about 

 the glass, stuck against the sides of it. 



Three or four years ago all the leaves of the trees in my garden, and all the 

 blossoms were so devoured by the worms or creeping insects, that in the spring 

 there was not one remaining ; and I imagined that few of those insects, for 

 want of food, would arrive to their change, that is, be turned into flying crea- 

 tures ; however I took several of those dried and consumed leaves and blossoms, 

 together with the webs, and shut them up in a box, and the following year I 

 perceived that several little and different sorts of flies were produced by them. 



Concerning Crabs Eyes. By Mr. Charles King. N° 266, p. 672. 



I cannot give you any satisfactory account of the stones in the heads of craw- 

 fish, for I never made any observations but casually, and without any design 

 of a particular account of them. I only remember in general, that they are 

 always on the outside of the stomach, while the old coat sticks on the back of 

 the fish, and pass into the stomach as soon as they cast their coats, having 

 never seen them on the outside when they have changed, nor within before. 

 And I also remember the males change their coats a considerable time before 

 the females ; for these always keep theirs till they have parted with their young 

 from their tails. 



On the Insect called Libella.* By M. Poupart. N°266, p. '673. 



The libella is a flying insect, called in France demoiselle, from the variety 

 of its colours, transparency of its wings, and its stately flight ; they also call it 

 perla, from the figure of its head, or rather from the roundness and colour of 

 its eyes. It is called by the Latins libella, perhaps, because in flying it usually 

 carries its body horizontally. It is divided from space to space into rings, by 

 means of which it can compose angles with its body, whose lines it can make 

 longer or shorter as it finds occasion. These diff^erent sections serve to the 

 motion of this insect, as we know the tail does in birds, and, as they are 

 lengthened or contracted, they carry themselves according to their various incli- 



* The modern name of this genus of insects is //ie//«/a. An ample history of its nature and trans- 

 formations, accompanied by figures, may be found in the works of Reaumur and Roesel. 



