148 



ZQology, 



and in so doing several passed so near to each otiier, that I cannot con- 

 ceive, as they passed in opposite directions, that any current of air conveyed 

 them, as two opposite currents could scarce exist so often close to each 

 other. I observed that those which passed near enough to distinguish their 

 forms, all flew with their backs downwards. I do not know if these facts 

 will at all bear on the controversy between Mr. Blackwall and Mr. Murray. 

 Such as they are you have them. — JoJm Thompson. HuII^Ju1j/2Q. 1829. 



Winter Quarters of Lepthra mwans. — The most trivial facts connected with natural history 

 may tend to illustrate the science, and tend possibly to other discoveries. I shall, therefore, 

 make no apology for communicating the following :— On examining some stems of the ^rundo 

 Phragmltes, wnich I had drawn up by the roots from the side of a pool, the bottom of which was 

 thick mud, 1 observed the portion of the plant immediately in con- 

 tact with the root rather thickly studded with certain egg-shaped 

 transparent brown cocoons {fig. 30. a), which I concluded to be 

 the winter covering of some aquatic insect in its larva state. On 

 examining these water-proof cases, which were about half an 

 inch long, I found each to be the winter quarters of the Leptura 

 micans (A). On extracting the insect, it appeared to be in a semi- 

 torpid state, but j)erfectly well fed, and in good condition. We 

 know that many of the Cole6ptera retire to peculiar haunts for 

 the purpose of hybernation ; but I am not aware that there are 

 many facts on record proving that in the perfect state insects of 

 this order construct habitations suited to the occasion : and it is still more extraordinary, that the 

 imago of this species, which invariably dwells above the surface, and is capable of active flight, 

 as must be known to every naturalist, who in the summer season, during the heat of the day, has 

 watched the reedy boundaries of a marsh or pond, should descend some feet into the water, and 

 there construct a dwelling impervious to water, in which, so far from its being their natural 

 element, they are soon drowned. On the whole, I am more inclined to suspect that the old ones, 

 at the close of summer, lay their eggs, which hatch in due time, and that the larva is the architect 

 of these cocoons, in which, after a speedy change, the perfect insect is developed, and remains 

 cradled in its tomb till the genial suns of the next season call it forth. It should be remarked, • 

 however, that on exposing these cocoons to water heated to about 85'^, they evinced no symp- 

 toms of increased activity. By what extraordinary process, moreover, do these submarine 

 sleepers continue to construct a case from which water must have been excluded during the whole 

 operation ? — E.S.,F.L.S. 



Ants and Aphides. — Sir, The ants and their interesting habits have something so much bor- 

 dering upon the marvellous, that many persons have been induced to discredit much which has 

 been published upon the subject ; but, singular as their history appears, every day's observation 

 proves that much more might be written on their instinctive carefulness and extraordinary saga- 

 city. The annexed sketch {fig. 31.), may furnish additional interest to their history, as well as 



pleasure to your readers. A goose- 

 qi berry tree in my neighbourhood 



"^■^ was observed to be infested by 



aphides, on which a number of 

 black ants were seen actively em- 

 ployed upon the leaves and fruit. 

 On a closer examination, they were 

 discovered to be constructing mud 

 roofs, or archways from the stem 

 of the plant to some of the fruit, 

 leaving a part of the same un^ 

 covered. Within this dome, of 

 archway, a small flock of aphides 

 were studiously retained by the 

 ants. Thus sheltered from the rain, 

 which has so abundantly fallen this 

 summer, they nourished them-,, 

 selves, and afforded their sagacious 

 shepherds that honey dew which 

 it is well known they seek with so 

 much assiduity. Over some of these 

 archways they had carefully glued 

 a leaf of the tree, so disposed that 

 the rain might easily glide off, and 

 thus the mud roof was rendere* 

 impervious to the wet. As a fur- 

 ther instance of instinct, the fruits thus erected upon had been chosen, or first ascertained 

 to be firmly fixed between two of the spines, as in the sketch, or confined by the leaves and 

 branches of the tree. Linnaeus truly called the aphides the cows of the ants.— JF. C. L. Guem- 

 sey,Sept.2\. 1829. 



The Water Beetle. — I observe that one of your correspondents no- 

 tices the probability of ponds in elevated situations being stocked with 

 fish through the agency of the water beetle. If this active and voracious 

 little creature were really useful that way, it might in some measure atone 

 for its other mischievous propensities ; for I do not know a more destruc- 

 tive little insect to fish themselves, besides devouring the spawn. A neigh- 

 bour of mine lost several hundred of the fry of the gold and silver fish by 

 this little pest ; and, to leave no doubt about the matter, he caught one, 

 and placed it in a large basin of v/ater, to which he shortly after added a 



