EHRENBERG ON ORGANIC MOLECULES AND ATOMS. 57.'5 



P i^_ of a line ; tlie partitions of these monad-bellies will be but 

 4 600000 ^^ 6400000 ^^ ^ French line in diameter, &c. I have besides 

 seen rudiments of eyes in the monads to which I have given the name 

 of Microglena monadhia, and which are y-gg of a line in diameter. 

 These often fire-red eye-points appear in larger infusoria to be a fine 

 granular red pigment, but whose granules, perhaps first covered by 

 many finer pigment granules, are small lenses, &c. ; and although I will 

 not lay particular stress on the fineness of these parts, yet the existence 

 of eyes, however rudimentary they may be considered, allows of the 

 possibility that even in the smallest species they may be present, and 

 tends to lead us to a not so proximate finity of organic molecules ; it 

 may even give a useful hint for considerations on the elements of 

 colours* and the theory of light. 



Finally I must not pass over in silence a direct observation which 

 lias confirmed me in the ojjinion that the small organic, apparently hy- 

 pothetical magnitudes really deserve great consideration. By the 

 kindness of Professor Enslen, who in the park near Berlin has a pecu- 

 liar contrivance for the public use of a solar microscope, I have made 

 with him several experiments. By observing Monas atomtis well filled 

 with indigo, I discerned among them wandering shadows of smaller 

 monads, which could not by a vast deal reach to giJmT ^^ ^ ^^^^' ^"^1 

 which I could not atall discern in the same water with the most powerful 

 magnifier of Chevallier's microscope : perhaps their transparency might 

 be one reason. Whether these animalcules then be the brood of 

 Monas atomus, or various species of still unknown infusoria, it follows 

 from the observation, that ^yy of a line is not at all the limit of or- 

 ganized beings for observation. It was on this account that I called 

 the smallest monad, which increases so plentifully in animal solutions, 

 and which resembles the 3Ionas Termo, page 9^ of my memoir of 1830, 

 the Twilight-Monad ; because from this point a new sy tern of organized 

 beings may easily be opened by means of increased power of vision. 



Let not these calculations be disregarded as appearing to be playful ; 

 they are so far in earnest that they are founded on the contemplation 

 of nature, and are not to be considered as a groundless speculation. 



• In regard to the pliaenomena of colours in high achromatic magnif3-ing 

 powers, I will just mention by the way that in some very small beautiful green- 

 coloured globular infusoria from t-^ti to -^^ of a line in size, and especially in 

 Micro<jle7ia volvocina, at a power of 400 or 800 I always see a fiery red ring 

 round the animalcule. This ring is evidently an optical spectrum ; but 

 how to be explained ? Perhaps tlie animalcule is thickly covered with fine hairs ; 

 and this hairiness causes perhaps, by refraction of light or play of colours, this 

 phsenomenon, which is only apparent in the periphery. Other similar beautiful 

 green animalcules never exhibit a red ring ; moreover this red is quite similar 

 to the yellowish beautiful red which the pigment of the eyes in the Rotatoria 

 .and Polygastrica exhibit. 



