38 THE POPULAR SCIENCE MONTHLY. 



circumstances, but pretty uniform in the same solution. They are in 

 length from -j-g^g-g- to ao * 06 of an inch, and in thickness from -gu-jj-g-Tr to 

 4iro~o o" f an inch. The rods are formed of a series of granules placed 

 end to end, and their appearance has been likened to a number of fine 

 needles embedded in a thin film of glue. They often present a joint 

 or line in the middle, dividing them into two equal parts. " Their 

 movements are frequently of a more or less rapid, oscillating, or irregu- 

 larly rotating character; though at other times they maybe seen dart- 

 ing from place to place, either directly or in curves of various descrip- 

 tions. All gradations exist, in fact, between movements which suffice 

 at once to stamp them as living things, and mere slow oscillations, the 

 presence of which alone may make us doubtful as to whether we have 

 to do with living or dead organisms." 



Along with the plastide-particles and the bacteria, there appears 

 one of the lowest and simplest of organic bodies the Torula, or yeast- 

 plant (Fig. 1, C). The torula is a simple cell, possessing a cell-wall 

 formed of a thin, homogeneous membrane, and containing a soft forma- 

 tive layer composed of protoplasm. These cells are about ^oVo f 

 an inch and smaller, and multiply by budding or gemmation, being 

 usually seen in chains, or clustered groups. Vibriones (Fig. 1, D) are 

 described as jointed bodies, composed of long, rod-like segments, bent 

 at various angles, which exhibit certain slow movements either as 

 mere bending of the body, or else an actual undulating progression. 

 In size they may vary from that of the largest bacteria, up to a body 

 j-J 7 of an inch in length, by l7 ^ 00 in breadth, though there is no defi- 

 nite limit to their dimensions. The Spirilla (Fig. 1, E) are less common 

 organic forms, characterized by the most active movements, and in 

 which the body is thread-like, though twisted into the form of a helix, 

 or spiral. Leptothrix (Fig. 1 F) is a name applied to certain filamen- 

 tous objects that are generally motionless, and often not much thicker 

 than vibriones. They may be either straight or undulating in outline, 

 and perfectly plain, or marked by minute segmentations, after the 

 fashion of the larger fungous filaments, into which it is said they some- 

 times develop. 



Within a few years past, attention has been called by Prof. Haeckel 

 to certain of the lowest forms of organic life, which he considers inter- 

 mediate between the animal and vegetable kingdoms, and by which 

 they are connected. These he calls the Protista, meaning, first of all, 

 primordial. This primordial organic kingdom, Haeckel divides into 

 ten groups, the lowest of which he names the Monera, which includes 

 certain minute jelly-specks termed protomceba and protogenes. Prof. 

 Haeckel says : " I have called these forms of life standing at the lowest 

 grade of organization monera. Their whole body, in a fully-developed 

 and freely-moving condition, consists of an entirely homogeneous and 

 structureless substance, a living particle of albumen capable of nourish- 

 ment and reproduction. These simplest and most imperfect of all 



