66 M. Ehrenberg's Researcltes on the hifusoria. 



the absence of a spot of coloured pigment does not prove that 

 the brain is awanting ; for we know there exist species among 

 the mammiferae in which the eyes waste and almost disappear, 

 whilst the brain does not participate in this diminution. It is 

 indeed probable, according to all that is known, that nervous 

 matter exists throughout the whole of the animal series. 



The genus Daphnia, then, being provided with simple and 

 compound eyes, the Cyclops with simple eyes only, and, finally, 

 the connection of these eyes with the brain being very conspicu^ 

 ous, our author contends that these are proofs sufficient to dissi- 

 pate all the doubts which have hitherto existed concerning the 

 nature of the black-coloured pigments which are placed in the 

 interior of the head of many animalcules. Add to this, that 

 M. Ehrenberg has, in a great number of instances, very dis- 

 tinctly observed the knots of medullary substance communicate 

 with the spots of red pigment in the Rotatoria, and has repre- 

 sented them in many, as in the subjoined figures. These are the 

 reasons which have led him to maintain the existence of nerves 

 in the Infusoria, reasons which are not hypothetical, but con- 

 firmed by a series of experiments. 



In conclusion, it may be remarked, that the whole of M. 

 Ehrenberg's observations have led successively to the recogni- 

 tion, in the Infusores, the smallest of all beings which man can 

 perceive by those means of investigation which optical instru- 

 ments supply, all the systems of organization which consti- 

 tute the essential part of the organization of man ; and these 

 systems are not rudimentary, but, after their kind, as perfect as 

 in man, although with diff'erent forms ; and it may be perceived 

 that the animal organization in man, and in the Rotatoria, and 

 even in the Polygastric Monad, consists of a single type, which 

 predominates throughout the whole series of animals. And 

 moreover, every thing that he has advanced on these organized 

 beings, so infinitely small, is not a bold and groundless philo- 

 sophical speculation, but solely the result of innumerable ob- 

 servations, which have not yet been brought to a conclusion, 

 notwithstanding the length of time he has already spent upon 

 them. 



