490 



SYSTEMATIC HISTORY OF THE INTFSORIA. 



given. Most of them are inhabitants of water in which organic matter is un- 

 dergoing decomposition. 



The Monads of Ehrenberg are arranged under two divisions, according to 

 their external form. The first division contains all those of a globular or oval 

 shape (globular Monads) ; the second those of a lengthened form, the length 

 being more than twice the breadth (elongated Monads). 



A. — Globulab Monads. 



MoNAS Crejnisculum (xvni. 1). — The 

 smallest of all living creatm'es; of a 

 spheroidal form, and hyaline, although, 

 when seen in masses, with the naked 

 eye, of a whitish hue. They are active, 

 and feed on animal as well as on vegeta- 

 ble substances, and are found in water 

 holding animal matter in solution ; but 

 as decomposition proceeds, they die, and 

 their bodies rise to the surface of the 

 water, and form a thick and colourless 

 gelatinous stratum. Rarely 1-1200" in 

 diameter ; never larger. 



M. Termo (M.), so named from its 

 having been supposed to be the limit of 

 animal organization ; globular, active, 

 herbivorous ; found in stagnant water ; 

 increases rapidly where there is an 

 abundance of vegetable matter imder- 

 going decomposition. 1-6000" to 

 1-12000", and less. 



M. Guttula (M.). — Bound, inactive ; 

 may be preserved by drjdng ; 12 di- 

 gestive vacuoles seen by the aid of in- 

 digo or carmine ; surface appears granu- 

 lated. In vessels of water containing 

 plants or flowers. 1-2300" or less. 



M. vivipara. — Spherical, inactive. In 

 stagnant water; coloured. 1-620" or less. 



M. grandis. — Spherical ; colour green- 

 ish, except near the mouth ; filament 

 short, l-3rd or l-4th the length of the 

 body ; motion sluggish. In marsh water, 

 very rare. 1-430". 



M. hicolor. — Globidar; colourless, ex- 

 cepting one or two green spots within 

 it ; attenuated anteriorlv ; motion vacil- 

 lating. 1-1440". 



M. ochracea. — Globular ; of a yeUow- 

 ochre colom*. In water-courses. 1-6000" 

 at most. 



M. erubescens. — Circular ; rose-co- 

 loured ; motion slow but continued. In 

 salt water. 1-1728". 



M. vinosa. — Globular, colour of red 

 wine ; motion tremulous ; rejects co- 

 loured food. In vegetable infusi<|iis. 

 1-12000" to 1-6000". 



M. Kolpoda. — Colourless, oval or egg- 

 shaped : motion vacillating. In water 

 in the silver mines of Siberia, 1-7200". 



M. Enclielys. — Colourless ; continuous 



slow motion. In marsh water. 1-1200" 

 to 1-960". 



M. Umhra. — Ovate, colourless ; motion 

 rapid. Among fi-esh Confervae. 1-2400" 



M. hyalina. — Ovate, colourless; ac- 

 tive, and seems to leap or j imip. In stale 

 water in glass vessels. 1-6000" to 1-2880". 



M. gliscens. — Ovate, colourless ; mo- 

 tion gliding. In infusions of the sting- 

 ing-nettle. 1-4500". 



M. ovalis. — Oval, colomless ; motion 

 tremulous. In water from the Anodonta 

 Mollusca. 1-9600". 



M. i^/^m. — Oval, colourless; rotary 

 and vacillatino- motion. In clear fresh- 

 water. 1-1440" to 1-1200". 



M. Punctum. — Egg-shaped ; revolves 

 on its longitudinal axis (xviii. 2) ; the 

 lower figure exhibits one vmdergoing 

 lougitudiual division. In water with 

 tannin. 1-1150". 



M. Semen. — Large, green, rather obo- 

 vate, subcompressed ; anterior end di- 

 lated, roimded ; posterior attenuated ; 

 oral apertm-e (!) triquetral beneath the 

 frontal portion ; vibrates by numerous 

 cilia (!). Length 1-48"' ; motion vacil- 

 lating, slow ; a central, hyaline, subglo- 

 bose gland ; ovides large, green, ovate. 

 It readily shows by diffluence the ova, 

 gland, and bacillaiy spicida. Frontal 

 end exhibits rugae extending fi'om the 

 mouth. With deca}'ing Sphagnum from 

 marshes, Berlin. Smely this organism 

 is not a Monad. 



B. — Elongated Monads. 



M. cylindrica. — Solitary, elongated, 

 colomless ; motion revolving. In salt 

 water. 1-1150". 



M. Okenii. — Elongated, red; motion 

 revolving, vibratory, social. In running 

 water. 1-2300". 



M. deses. — Conical, green, solitaiy. In 

 water fr'om hiUs. 1-1200". 



M. socialis. — Conical, colourless, so- 

 cial. In water-butts. 1-700". 



M. Jlavicam. — Top-shaped ; social ; 

 motion gliding. In ditch-water. 1-1720". 



M. simplex. — Spindle-shaped ; colom- 

 less ; motion gliding and rotary. In 

 water of the Nile, and at Berlin. 1-1720". 



M. inanis. — Fusiform, colourless ; mo- 



