INFUSORIAL ANIMALCULES. 21 



The action of acetic, acid and of electricity, on these minute 

 organisms, have been proposed as tests, but hitherto the results have 

 been unsatisfactory. 



This imcertairity in distinguishing plants from animals, coupled 

 with the observation of some peculiiu" phenomena in the production 

 of spores in the lower Alga?, led those distinguished naturalists, 

 linger and Kiitzing, and others, to believe iu the transition of some 

 foims, from an animal to a vegetable existence, or vice versa. It 

 seemed to Kiitziag, that there are beings in which animal and 

 vegetable life ai-e so iutimatcly blended, that the kind of exist- 

 ence manifested, will depend on the predominance of one or of 

 the other, and this too, without a necessaiy change of form. 

 Uuger goes fiu'ther in liis belief in the transformations of Algae 

 into animals, and the reverse; but, Siebold declares "such an 

 opinion is unphilosophical ; for, be the natiu'e of any being what 

 it may, vegetable or animal, A^'e must consider it fixed and un- 

 changeable. Moreover, the apjiearances on which Unger's views 

 rested, ai'e easily understood when we recognize the presence of 

 cilia in both animals and plants, a fact, that natiu'alists overlooked. 

 (Dissertatio de fiaiibus inter reguum animale et vegetabile constitu- 

 endis, Erlangse 1844.") 



M. Thm'et says the error of belicAdng in the metamorphosis of 

 Alg£e, has arisen from the confbim.ding together aggregations of 

 globules of similar appearance, but of very different natiu-e, — as, 

 Infusoria, Zoospores of Algfe, Spores of Mosses, Gonidia of Lichens, 

 «&;c. ; a confusion which has led some to suppose that an Algte can 

 produce not only another of a species or even germs different to 

 itself; but also give origin to a Moss, Hepatica, or Lichen, according 

 to the circimistanccs luider which the germ was placed. " For my 

 part, I never was witness of any such marvellous transformations. I 

 have never seen a Binclmis produce an Algae, nor an Algae a true 

 Diselmis. On the contrai'y, whenever I have had the opportvmity of 

 following, for a sufficiently long time, the germination of a zoospore, 

 I have seen produced, not an Algae of another species, still less a Moss 

 or a Linchen, but an individual evidently belonging to the same 

 species as the parent plant." 



