ZOOLOGY: 587 



way reached the wide oceau. There they will have sunk, their de- 

 velopment accomplished all through dt^])ths full of danger and more 

 and more uncongenial, and a few of them will have settled on the bot- 

 tom of the abyss, and fewer still will have come to thrive there. Among 

 these some will long have their original character, and but slowly beeu 

 modified, while others will have exhibited a latitude of variation un- 

 known or rarely seen where they came from, but upon the whole there 

 will be reasons for assuming the less altered forms to be new comers, 

 the more deviating to be old inhabitants of the deep." 



Organisms in ice.~A Philadelphia gentleman gave Prof. Joseph Leidy, 

 for examination, a vial of water obtained from a lump of ice which had 

 been used to cool ordinary drinking water. '' From time to time, among 

 some sediment taken from the water-cooler, the gentleman had observed 

 what he supposed to be living worms, which he susjiected were intro- 

 duced with the water into the cooler and not with the ice." On exami- 

 nation of the water melted from this ice. Professor Leidy was "surprised 

 to find a number of worms among some flocculent sediment, mainly con- 

 sisting of vegetal hairs and other debris. Besides the worms, there were 

 also immature Anguillulas, and a number of Rotifer vulgaris, all living. 

 It would appear that these animals had all beeu contained in the ice, 

 and had been liberated on melting. It was an unexpected source of 

 contamination of our drinking water that Professor Leidy liad previ- 

 ously supposed very improbable. The little worms he was not familiar 

 with." 



A study of the worms showed that "they belong to the family Lum- 

 bricidw, and probably may be an undescribed species of Lumhri cuius. 

 They are white or colorless, from 4 to G millimeters long by a third of a 

 millimeter in thickness;" there are about thirty segments. "Several 

 dead worms swarmed in the interior with large, ovate, beaked, ciliated 

 infusoria, measuring from 0.05 to O.OG '""^ long by 0.0-4 to 0.048'""" broad." 

 {Froc. Acad. Nat. ISc. Phila., 1884, p. 2G0.) 



Microscopic fauna in water reservoirs. — An accidental breaking of a 

 valve, necessitating the drawing off of the water from the Fairmoiint 

 reservoir, was taken advantage of by Mr. Edward Potts to study the 

 minute fauna to be found. 



" The commensal habit of many of the lower animals who feed by 

 the creation of ciliary whirlpool currents has beeu frequently referred 

 to; the weaker current-makers, such as vorticellae, stentors, and the 

 errant and tubicolous rotifers, planting themselves about the heads of 

 the stronger polyzoa to supply their own nets with what may have es- 

 caped from the others. The same instinctive in-iuciple which leads all 

 these to locate themselves most i)lentifull3' amongst the stones in the 

 rapids of streams, was particularly noticeable in promoting their ag- 

 gregation ui)on and in the neighborhood of the inlet and outlet gates 



