■60 



THE AQUARIUM, JULY, 1896. 



HS the plant is provided for by all 

 bounteous Nature's hand ; as the sun 

 goes down behind the mountains, or is 

 shrouded behind a cloud, its light is 

 hidden but for a time to burst forth 

 again resplendent. 



As the river flows, traveling on- 

 wards to mix its waters in the un- 

 known depths of the ocean, leaving as 

 it were forever the hills from whence 

 it sprung, it is but to assume the form 

 •of vapor to replenish those springs. As 

 the reed bird builds its nest, a home 

 for its little ones yet unborn, an un- 

 known sweet voice of kindness bids it, 

 she knows not why, thus look to the 

 future. Yes, the river is rushing for- 

 ward, the clouds are hurrying onward, 

 the winds are sweeping past, because 

 here is not their rest. Ask the river, 

 ask the clouds, ask the winds where 

 they go. Another land ! Ask the 

 great sun as he descends out of sight 

 where he goes. Another land! And 

 when the appointed time shall come 

 man also must go. Where ? To that 

 other land to which these voices of na- 

 ture have all along directed him — into 

 the presence of nature's God. 



FISH PARASITES. 



BY A. W, EGBERTS. 



The leeches which commonly swim 

 free in the water, and only occasionally 

 attach themselves to the bodies of ver- 

 tebrate animals to drink themselves 

 iull, have their nearest relations in 

 those which attach themselves to the 

 •exterior of fishes and crustaceans. While, 

 however, the free swimming leeches 

 have ringed bodies, the parasitic leeches 

 ■of fish and crabs have soft and smooth 

 bodies, especially in the Malactobcielles, 

 In other words, there are leeches which 



occas-ionally prey upon warm-blooded 

 animals, and are hardly to be called 

 parasites. Others are to be found only 

 on the skin of cold-blooded vertebrates, 

 and, finally, those of thoroughly para- 

 sitic character, which adhere to crabs 

 and soft-skinned animals. The Po7i- 

 tohdeJla muricata is most commonly 

 known as the skate sucker from the 

 fact that it is most frequently found 

 adhering to the different families of 

 the skate or ray family of fishes. This 

 genus of marine leeches can be gen- 

 erally distinguished by the numerous 

 tubercles on the rings of the body, 

 which produce a very curious effect. 

 The prevailing color of the skate sucker 

 is a greenish gray. 



These marine leeches are provided 

 with a large and powerful sucking disk, 

 by which they can maintain themselves 

 in a horizontal or i:)erpendicular posi- 

 tion ; but their most common position, 

 when at rest and attached to inanimate 

 objects, is a spiral, the head being in 

 the centre. 



On my return to the aquarium one of 

 the large fresh water tanks, which had 

 been neglected for several months, had 

 become so infested with a small variety 

 of parasitical leech that it was with 

 difficulty the glass front could be kept 

 clear of them. Even the extreme tops 

 of the aquatic plants growing in the 

 tank swarmed with thousands of them 

 constantly extending themselves in 

 their endeavors to catch on (they not 

 being free swimmers) to the tails and 

 fins of the lake dog fish, or the large 

 specimen of fresh water eels contained 

 in the tank. The eels instinctively 

 avoided resting on the floor of the tank 

 or coming in contact with the plants or 

 rock-work sides of the tank, but re- 

 mained suspended night and day in the 

 open clear mid-water. Still, with all 



