98 



KIDD'S OWN JOURNAL. 



begun, for the instant it should let go its an- 

 chorage, it would be hurried down the perch's 

 fauces into the gulf of the stomach, and en- 

 tombed in the food which is there exposed to j 

 the action of the gastric juice. But the Ac- 

 theres percarum is itself attacked by another 

 parasite of more diminutive form ; a very 

 small species of mite, called the Gamasus 

 scabiculus, finds an opportunity of bleeding 

 the bleeder, and preys upon its blood as it 

 does upon that of the perch. The saliva, also, 

 with which it is covered, becomes a sort of 

 muddy pond, in which numbers of Infusoria 

 of the tribe Vorticella, fatten and feed upon 

 the back of the Actheres. The parasites are 

 thus multiplied upon one another ; aud each 

 species affords sustenance for others inferior 

 to itself in the scale of being. The deeper 

 we carry our researches into nature, the more 

 does it seem to teem with living wonders ; and 

 its population to increase, the more diminu- 

 tive that they become. 



The next animalcule that we shall mention 

 is the Pterojrtes, a species of bat-mite, which 

 infests the wings of this night-loving bird. 

 As this organ of flight is a large and naked 

 membrane, it would appear almost imprac- 

 ticable for an insect to fix itself so firmly 

 upon the bare surface as not to be cast off by 

 the violent flapping. But the creature is pe- 

 culiarly constructed to meet this emergency. 

 Its eight feet are furnished with vesicles 

 which it can use as suckers, and firmly cling 

 to the smoothest object. Like a ship in an 

 open bay, sheltered from the ocean's waves, 

 but not from the violence of the winds, which 

 rides in safety by anchors thrown out from 

 various quarters — so, thePteroptes fixes itself 

 by as many of its feet as it deems necessary 

 to its security. But lest any unwonted mo- 

 tion or sudden jerking should drive it from 

 its moorings, it possesses the singular power 

 of instantly turning up as many of its legs as 

 it pleases, and laying hold of the object which 

 was previously above its head. It can walk 

 in this inverted position as if upon its back. 

 In seasons of great tumult, it may be seen 

 with four legs upwards, ready to grasp either 

 the ground or the roof of its strange dwelling. 

 Such an organisation would be useless to a 

 parasite which nestles amongst feathers or 

 upon a downy skin; it is only available to a 

 creature which lodges in the wrinkles of a 

 bat's slippery wing. The dangers of its situ- 

 ation are provided against by this unique ex- 

 pedient. 



Another parasite which infests the same 

 bird, has been termed the Bat-louse. The 

 structure of this animal also is contrary to 

 the usual process of nature. Its head is 

 placed in the back of the thorax, behind the 

 attachment of the four legs. There is a cavity 

 in the back terminating in a kind of pouch, 

 into which the creature throws back its head 



when it is going to feed, and continues in this 

 position whilst engaged in suction. It 

 therefore takes its food with the belly up- 

 wards, and its head ensconced in the hole of 

 its back ! But this little monster, if so it 

 may be called, is furnished with an eye, and 

 with antennae and feelers, so that it knows 

 well what it is about, and where it is going. 

 Its legs are not fixed, as is usual, in the lower 

 part of the trunk, but in the upper margin, 

 and its motion is so swift as to resemble 

 flight rather than creeping. Whilst it is feed- 

 ing, we might easily mistake the under for 

 the upper part of its body, were it not for the 

 form of its legs. It seems to have been made 

 on purpose to show how manifold are the 

 designs of the Creator, and what strange 

 forms of being can be produced by his skill ; 

 each complete in itself, and perfectly adapted 

 to its particular sphere of action. It is this 

 that renders an investigation into the secrets 

 of natural history so satisfactory in the results, 

 that we find every animal equipped with all 

 necessary organs, and placed in a situation 

 suitable for their exercise. This is the per- 

 fection of a creature. 



Another parasite deserves special notice, 

 from the singularity of its structure, as a dou- 

 ble bodied animal. The Diplozoon inhabits 

 the inner gills of the Bream fish. What tempt- 

 ed a naturalist to look for anything in such 

 a locality ? As the leaves of this organ are 

 in constant motion, and a perpetual stream of 

 water passes through them, we might imagine 

 it to be a very insecure place for feeding. 

 But the Diplozoon is provided with all the 

 requisite tackling for such a station ; like a 

 ship in a river, firmly moored to buoys fore 

 and aft, and on either side, so that it rides 

 safely in the same spot — whether the tide ebbs 

 or flows, and whether the water is high or low. 

 The Diplozoon has two bodies, united at 

 their centres, leaving the upper and the un- 

 der limbs free of each other. Being provided 

 with a number of suckers from each half, it 

 attaches itself at once to two leaves of the 

 gills, with so firm a hold, that it is not moved 

 by the constant motion of this slippery or- 

 gan. Each of its upper limbs has a triangu- 

 lar mouth, with a sucker to steady it in per- 

 forming its operations. The organ of suction 

 resembles a tongue, which appears to be in- 

 cessantly in exercise. The alimentary canal 

 of this wonderful creature branches into both 

 its lower sides. The circulation of its blood 

 is carried on through four principal channels, 

 each half of the animal having an exterior 

 and interior tube ; in the former of which the 

 blood flows upwards, and in the latter down- 

 wards, the circulation being performed with 

 great force and rapidity. The generative 

 organs are also double. The lower lobes 

 always move in the same direction, but each 

 of the upper arms seems to have a separate 



