INFUSORIAL ANIMALCULES. 21 



ied benevolence displayed in every manifestation of His infinite power ! In respect 

 to the Polygastrica, Ehrenberg claims that the red-colored specks, which he ob- 

 served in many organisms that he included in this class, are true eyes; but from 

 this conclusion other microscopists dissent. Ehrenberg insists much on the red color of 

 the speck as a distinctive indication of a visual organ, but other colors prevail in the 

 known eyes of insects. If it is admitted that these eye-specks have a general sensation 

 of light, their optical nature is not proved, since organisms destitute of these exhibit 

 a like sensibility of the presence of light. The eyes of the Rotatoria are generally 

 red, and most of the animalcules belonging to this class have two of these organs. 

 In some three are perceived ; while one kind especially has the benefit of seven or 

 eight on each side of the head. A diversity exists in the arrangement of the eyes; 

 in many instances they are placed in a line, side by side, in others they form a tri- 

 angle. In some animalcules they are arranged in a circle, and in two species they 

 unite in clusters on each side of the head. 



REPRODUCTION. Animalcules multiply in several ways. First, they proceed from 

 eggs. Secondly, they are brought forth alive. Thirdly, they increase by the 

 growth of buds issuing from the body of the parent; the buds sprouting out and be- 

 coming themselves perfectly organized animalcules. Lastly, they are propagated 

 by self-division, the body of an animalcule separating into two or more individual 

 beings. 



The same animalcule is not always confined to a single mode of reproduction, but 

 its countless offspring may come into existence by one or more of the ways just de- 

 tailed ; one part being produced by self-division, another from eggs, and the re- 

 mainder originating in buds. This circumstance accounts for the amazing fecundity 

 of the Infusoria, which almost surpasses belief; even when limited to one method 

 of increase. The Rotatorial animalcules are propagated from eggs alone, and but 

 a few of these are deposited at a time; yet so quickly are the young matured, that 

 from a single animalcule millions will proceed in the course of a few days. Dr. 

 Ehrenberg kept one of this class of Infusoria for eighteen days in a separate vessel 

 of water; during this interval it laid four eggs a-day, and the young, when two 

 days old, laid the same number; so that, continuing to multiply at this rate, it was 

 found -that, under favorable circumstances, the offspring of a single creature would 

 amount, in the course of ten days, to one million; in eleven, to^four millions; and 

 in twelve days, to sixteen millions. This is the greatest increase that has actually 

 been determined by experiment. In the other class of Infusoria, the Polygagtrica, 

 the fecundity is much greater, inasmuch as they are endowed with more varied pow- 

 ers of reproduction. A single animalcule belonging to one of the larger kinds is 

 known to separate into eight, in the course of a day, by self-division; so that, mul- 

 tiplying at this rate for the space of ten days, it would increase to more than one 

 hundred and fifty million individuals. It likewise propagates from eggs, which 

 are seen in clusters like the spawn of fishes; and also by buds, that sprout from the 

 sides of its body. When all these facts are taken into view, it is evident that the 

 vast number of living beings, which in a few days spring from a creature as prolific 

 as this, is utterly beyond our powers of appreciation. In truth, this animalcule, which 

 is called the Paramecium, increases so rapidly in stagnant waters, in the ways that 

 have been mentioned, that some naturalists have supposed that they were produced 

 spontaneously from inert matter. 



