C H I R O T E S. 



worms, which is quite sufficient to prove that, in this 

 case at least, even a little knowledge of natural history 

 would not have been a dangerous thing. A medical 

 gentleman having observed these larvae very numer- 

 ous in the water of a well, in the neighbourhood of 

 Cork, considered them to be the true origin of the 

 common small thread-worm (Qxyuanu vermtcvlofii) 

 occasionally found in the human intestines, the former 

 differing only from the latter in colour. Had he, 

 however, but placed some of these worms in water of 

 a temperature equal to the human body, he would 

 soon have discovered that they were not long able 

 to bear the increased heat of their native element. 



Reaumur found the larva? of one of the species in 

 small brown paper-like cases, attached to various 

 leaves which had fallen into the water in the Bois de 

 Boulogne ; the cases were of a flattish spindle-shape, 

 somewhat resembling an oblong seed, they were 

 chiefly composed of silk, but Reaumur could not 

 ascertain whether fragments of leaves might not also 

 be employed in their composition. We are unable 

 to decide as to the precise species observed by this 

 author, but from his description it seems nearly akin 

 to the C. plumosus. The fore legs are much longer 

 than the others, and generally carried in an elevated 

 position by this insect, so that they might easily be 

 mistaken for antennaj ; moreover, they are generally 

 kept in continual motion, now elevated, now depressed, 

 whence the origin of the generic name, signifying a 

 kind of gesticulation with the hands. The pupa has 

 the head and thorax united into an oval mass, with 

 the abdomen long and cylindric ; from each side of 

 the thorax arises an elegant apparatus composed of 

 five long finely feathered rays disposed in the form 

 of a star ; the tail is also ornamented at its extremity 

 with a fine brush of hair. The fore legs, from their 

 general length, are inclosed in cases which, instead 

 of folding upon the breast in the same way as the 

 shorter hind legs, project from each side of the thorax 

 in a very peculiar manner. Messrs. Kirby and Spence 

 have given a very interesting account of the manner 

 in which the insect, upon arriving at its perfect state, 

 in which it is destined to pass its life in the air, effects 

 its escape from the puparium, or skin of the pupa, 

 the natural clement of which is the water. For the 

 extrication of the imago it is necessary that it should 

 remain quietly suspended at the surface, and more- 

 over that the thorax in which the opening for its exit 

 is to be made should be at least level with it, and 

 this is precisely what takes place. By a most singu- 

 lar and beautiful contrivance, not only is the pupa 

 which is specifically heavier than water enabled to 

 suspend itself without motion at the surface, but its 

 thorax which is the heaviest end is kept uppermost. 

 This is effected by the property which the centre of 

 the thorax has of repelling water, hence as soon as 

 the pupa has once forced this part of the body above 

 the surface, the water is seen to retreat from it on all 

 sides, leaving an oval space in the disk which is quite 

 dry, hence the attraction of the air to the dry part ol 

 the thorax is sufficient to overbalance the specific 

 gravity of the pupa. If, however, when the pupa is 

 suspended at the surface, a drop of water be let fall 

 upon the dry portion of the thorax, it instantly sink 

 to the bottom, the thorax which belongs to the heaviest 

 half being the lowest, but if the pupa be again brought 

 to the surface so that the fluid is repelled from its 

 disk, it remains suspended there without effort as 

 before. Just previous to the exclusion of the fly, th< 



dry part of the thorax is seen to split in the middle. 

 The air enters and forms a brilliant stratum resetn- 

 jling quicksilver between the body of the insect and 

 its puparium, and the former, pushing forth its head 

 and fore legs, like the gnat, rests the latter upon the 

 water, and in a few seconds extricates itself wholly 



Larva, pupa, and perfect Chironomus. 

 from the puparium. A more recent author has en- 

 deavoured to throw some doubt upon the mode of 

 solution of the manner in which the suspension is 

 effected, asking in reference to that part of Messrs. 

 Kirby and Spence's statement, which he quotes entire, 

 which relates to the sinking of the insect when a drop 

 of water is let fall upon it. " If so, we may ask what 

 becomes of the power of the thorax to repel water?" 

 We answer that, although the thorax may possess the 

 power to repel the water immediately surrounding it 

 in a quiet and undisturbed state, it does not follow, 

 and indeed it would be absurd to suppose that it pos- 

 sessed a power of repulsion sufficiently strong to resist 

 the increased force of a drop of water let fall upon 

 the heaviest portion of its body, especially at a period 

 when the feeble creature is just as it vvere upon the 

 point of bursting into life ; indeed in support of this 

 opinion, we again find the same author adopting 

 another idea of Messrs. Kirby and Spence, namely, 

 that these midges fly unwetted in a heavy shower of 

 rain, owing to their quickness of vision, since if the 

 drops, bigger than their own bodies, fell upon them, 

 they must be dashed to the ground, although he im- 

 mediately takes up the idea of repulsion which he 

 had before thrown down, and " unless it may be that 

 the drops glide off their wings as they do off the fea- 

 thers of a duck." Insect Transformations, 319, 367. 

 There are nearly a hundred British species of this 

 genus, some of which are remarkable for the elegance 

 of their colouring. Many of them form beautiful 

 subjects for the microscope. 



CHI ROTES. A genus of saurian reptiles, which 

 may be considered as intermediate between the lizards 

 properly so called and those serpents which have 

 rudimcntal bones of the extremities. From the cir- 

 cumstance of having only two feet, this genus, or 

 we may say, this species, for there is but. one, has 

 been rather absurdly called lihitana ; but as that is 

 the proper distinctive name of the human race in 

 natural history, and as no animal but man is possessed 

 of what can properly be called a hand, the extremities 

 of apes and monkeys being merely grasping feet, it 

 is of course improper to apply the term bimana to 

 any species but the human race. This animal is the 

 Lacerta lumbricoidcs of Shaw, but it cannot, strictly 

 speaking, be considered as a lizard, and it has uo 

 resemblance whatever to an earth-worm (lumbricits) 

 in any one respect, except colour. It is one of those 

 singular animals of which two or three are met with 

 i'.i Mexico, and which have always puzzled the syste- 



