the seeds of fungi, which he describes, on (he aiithoriiy o{ 

 Baron Munchausen," as at first hving and moving, but as 

 afterwards becoming fixed, and growing into fungi ; the 

 smut of grain, which, on the same authority, when mace- 

 rated in water, becomes an oblong hyahne animalcule: 

 lastly, in what he call his "Chaos Infusorium," he has 

 swept together all other infusorial objects, to which he has 

 added the contagion of fevers, the syphilitic virus, the 

 spermatozoa, the septic power of putrefaction and fermen- 

 tation, and even the cloudiness of the atmospliere in spring, 

 all of which he ascribes to living molecules, and thinks 

 they probably belong to this family.* 



It is remarkable that Linncens, with all his qualifica- 

 tions as a naturalist, upon these subjects, took his opinions 

 upon the authority of others, as appears from his own 

 account, without having made a single observation him- 

 self of the objects which he describes. 



Examples of the in:! perfect observations, and rash con- 

 clusions respecting the infusoria, which prevailed among 

 the learned of that day, need not be multiplied^ and we 

 pass to the next important advance in the developement of 

 this branch of natural history. This was made by Otto 

 Frederic Miiller, a Danish Counsellor, in a series of obser- 

 vations published in 1773, and, more especially, in his post- 

 humous work, published in 17S6. in which he divides the 

 infusoria into two classes, viz : those which have, and those 

 which have not, visible external organs; the former he calls 

 Bullaria, the latter Infusoria. J This was the first attempt 

 to make a systematic classification of these objects accord- 

 ing to certain characteristics in their form, and although 

 the basis of this classification was uncertain, and the cause 

 of much confusion, by bringing into the same class objects 

 that in the most material points, were widely different, yet 



*LinuEei Systema Naturae, Yol. 1, Part 2, p. 132C, 

 JMuller Auimalcula lufusoria, Pra^f. pp. 8, 28. 



