ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 617 



Infusoria in "Dew." — Mr. W. S. Kent gathered,* in Eegent's 

 Park and the Zoological Gardens, on a day of intense fog, a quantity 

 of grass satur:.i:ed with " dew," and submitted it to examination under 

 the Microscope without the addition of any supplementary liquid 

 medium. In every drop of water examined, squeezed from the grass 

 or obtained from its simple application to the slide, animalcules in 

 their most active condition were found to be literally swarming, the 

 material derived from each of the localities yielding, notwithstanding 

 their close proximity, a conspicuous diversity of types. Heteromita 

 lens and H. caudata were in all cases abundantly present, as also 

 minute actively motile Bacteria. Other types, such as Vorticella 

 infusionum, Dinomonas vorax, Hexamita inflata, Trepomonas agilis, 

 and Phyllomitus undulans, and a number of unidentified spores and 

 encystments occurred variously distributed among the samples 

 examined, but even these by no means exhausted the living forms. 

 Two species of Rotifera, Rotifer vulgaris and Theorus vernalis, 

 numerous Amcebce, Angiiillula, and various diatoms, chiefly motile 

 Naviculce, contributed their quota towards the host of active living 

 organisms that were found peopling more especially the lower and 

 decaying regions of the dew-moistened vegetation, the collection 

 as a whole being indistinguishable from the ordinary microscopic 

 fauna of a roadside pond. 



The data elicited through these observations carry with them, 

 Mr. Kent considers, an important significance, as Infusoria and other 

 minute forms of aquatic life were thereby shown to possess an area 

 of active vital distribution previously undreamt of. Water in its 

 stable and concrete form is no longer, as hitherto presumed, a 

 requisite concomitant of such vital energy. Secure in their spore 

 membranes or encystments, these microscopic beings slumber un- 

 disturbed throughout the dry summer days, awaiting only the fall of 

 the evening dew or passing shower to re-awake to active life. The 

 conditions of existence of the animalcules thus found are obvious. 

 Encountered most abundantly on the lowermost blades, coloured 

 brown or yellow, which are begianing to decay, their purpose is to 

 break down and convert into new protoplasmic matter this otherwise 

 waste product. To maintain the balance here, however, and to check 

 the too rapid increase of the herbivorous monads, we find other types 

 such as Dinomonas, and various Ciliata, answering to the Carnivora, 

 developed side by side with and feeding in turn upon the plant-eating 

 species. 



Synopsis of Fresh-water Rhizopods.t — This is a condensed 

 account compiled by Professor R. Hitchcock of the genera and species 

 of all known fresh-water Ehizopods, in regard to which the author 

 points out that there is a broad field for original investigation, com- 

 paratively little being known about their modes of reproduction. It 

 is founded on Professor J. Leidy's recent treatise, and is intended as 

 a handy book of reference for those who may not possess the larger 



* Kent's ' Manual of the Infusoria,' i. (1880) pp. 140-1. 

 t Hitchcock, K., ' Synopsis of the Fresh-water Ehizopods.' (8vo, New York, 

 1881.) 56 pp. 



