Ma 



1892.] 



KNOWLEDGE 



95 



at present only of the Brachelytra, and remembering that 

 the general faaction of these insects in Nature is that of 

 scavengers, one sees that it is not at all unlikely that such 

 a function is discharged in the Ants' nests by at least some 

 of the species found therein. The need of some arrange- 

 ment analogous to sewage works, to dispose of the con- 

 siderable amount of excrement and other refuse matters 

 that must tend to accumulate in large communities of 

 Ants, is obvious, and it may well be that a share at least 

 of this work falls to the lot of the Ants' guests. Dr. 

 Michael has recently shown that in the nests of certain Ants 

 which he found in Corsica a kind of mite occurs, to which 

 the Ants seem greatly attached ; and a reason for this has 

 been suggested by him as being found in the fact that the 

 mites feed upon the bodies of dead Ants, and thus help the 

 members of the community to a solution of the vexed 

 question of the disposal of the dead, which cannot but be 

 a matter of perplexity to all societies and great aggrega- 

 tions of living beings, increasing in difficulty in proportion 

 to their size. In most cases the dead seem to be carried 

 out of the nest, and the Rev. Farreu White records a 

 curious instance in which some little paper trays, which he 

 had put upon one of the nests he kept for observation, 

 were used as cemeteries, the Ants dropping the dead 

 bodies of then' companions into them one after the other. 

 From the method in which the nest was in this case pre- 

 served for observation, viz., in a glass bell -jar, the bottom 

 of which was wholly occupied by the nest, it would seem 

 that this was the only method available by the Ants of 

 putting the corpses into any spot where they could really 

 be considered to hs removed from the nest, and the Ants 

 certainly deserve credit for the ingenuity of the device by 

 which they overcame the ditliculty presented by the glass 

 walls of their prison. 



No doubt in some instances the Ants and their guests 

 are found together merely because they happen to prefer 

 similar situations to live in. so that in such cases no 

 particular significance can be attached to the association. 

 Thus, if both delight to live under the bark of trees, or 

 amongst the roots of grass, here is a bond of connection 

 which will lead to their being found together unless either 

 party objects ; still, even in such eases, as the Ants, being 

 always the more numerous of the two, could if they liked 

 rid themselves of their companions, it is plain that the 

 association is not distasteful to them. The mere accumu- 

 lation of piles of vegetable fragments, such as those erected 

 by the mound-builders, would tend to induce beetles to 

 enter, as they often delight to lie concealed amongst 

 vegetable rubbish, and it is certain that if any such mound 

 wei'e deserted by the Ants, it would very soon be tenanted 

 by all sorts of dili'erent insects, as well as woodlice, 

 centipedes, millipedes, &c. That such indefinite tenantry 

 does not occur while the place is occupied by the Ants 

 must therefore be attributed to their own efforts. Again, 

 when fragments are brought in for addition to the mound, 

 it is quite possible that they may sometimes contain upon 

 their sm'face or in their interior either small insects or 

 the eggs of such, so that we have here another possible 

 means of the introduction of insects into the nests. On 

 the whole, therefore, it would seem to be, not so much a 

 matter of surprise that insects other than Auts are to be 

 found in the nests of the mound-builders, but rather that 

 then- number is not even greater than it is. Of course, 

 these remarks do not equally apply to those which do not 

 throw up mounds ; but then these do not, as a rule, yield 

 so great an alien population. 



We may now proceed to consider somewhat more in 

 detail some of the most remarkable of these companions 

 of .\nts. Of the Brachelytra, one of the most curious is 



Attnu'lfs emnriihiatus (Fig. 1). It is a reddish-brown insect 

 scarcely more than a sixth of an inch in length, but broad 

 out of proportion. It has a broad shield-like thorax, 

 ending in thin leaf-like edges at the sides, and in sharp- 

 pointed projections at the hinder angles. It has the habit 

 of curling up the tip of its abdomen as it runs about, and 

 this of course makes it look smaller than it really is. It 

 can also roll itself up almost into a ball. It is so peculiarly 

 shaped that it cannot easily be confounded with any other 

 British insect. It is found in the nests of several species 

 of Ants, especially the red stinging Ants {Mi/rmicti), the 

 blackish-brown l-'arinicn fmnt, and the shining black 

 F. fuUijinosii. A good many of the beetles may often be 

 obtained fi-om one nest, though always the Ants far 

 outnumber them. Wasmann records having found as 

 many as one hundred and fifteen specimens in one nest of 

 Mi/niika xcabriiii'ilis. This is one of the insects that 

 are very tenderly cared for by the Ants. It lives with 

 them on terms of the closest intimacy, being often 

 carried about by them from place to place. But more 

 than that, the beetles are, at least to some extent, 

 actually supported by the Ants, being fed by them 

 from their own mouths, just as they would feed their 

 young. If the beetle wants food, it approaches an Ant, 

 and planting itself in front, with its tail cocked up, begins 

 to stroke the Ant with its antennse ; the Ant soon responds 

 and passes food into its mouth, continuing the operation 

 perhaps for about half a minute, when it goes off about its 

 business. Sometimes indeed the feeding takes longer, 

 and some two or three minutes may be occupied in the 

 process. It must not be imagined from this, however, 

 that Atemclea has lost the power of feeding itself; this does 

 not appear to be the case, although, according to 

 Wasmann, the beetles flourish better when fed by the 

 Ants. The same observer has mentioned that the Ants 

 lick with apparent gratification certain tufts of j'ellow 

 hairs which are found on the beetle's body, as though 

 they yielded some secretion which was pleasant to the 

 taste. He also mentions that the beetles have the power 

 of exhaling an agreeable aromatic odour from a gland in 

 the abdomen, similar to, but stronger than the scent of 

 Mi/nnka, which arises from the head. The beetle enjoys 

 a good deal of freedom of movement, notwithstanding the 

 care of the Ants, and during the summer months it is not 

 to be found in the nests. But if the beetles at other 

 times manifest a tendency to wander too far, they are 

 picked up by their guardians and carried back again. We 

 have here, then, the case of a beetle which is closely 

 associated with the life of the Ants, and is carefully 

 tended, guarded, and fed by them, and yet which has so 

 far retained its faculties and powers almost if not entirely 

 unimpaired, and does not seem to have become degraded 

 by its dependence. That such, however, is not always the 

 case will be evident from other instances, which want of 

 space compels us to defer till next month. 

 (To be continued.) 



HOT SPRINGS. 



By Prof. J. Loci.u; Loblev, F.G.S. 



THEEMAL springs vary so gi'eatly in temperature 

 that to a large number the word " hot " is not 

 applicable, and yet these cannot be excluded from 

 consideration in connection with the subject of 

 Hot Springs, since they are essentially of the 

 same class of phenomena. 



All springs of water the temperature of which is higher 

 than that of the rocks from which they issue may be 



