the Origin of Intestinal Worms, SlT 



varying to infinity according to different external influences ; 

 and the infusoria were esteemed the first and simplest pro- 

 duction of this vital power of organic matter. Oken, the most 

 eminent of natural philosophers, declared (" Zeugung,'* 1805), 

 that the infusoria, although animals themselves, constituted 

 the essence of all other living bodies. Plants and animals, 

 man included, he supposed to be a mass of innumerable mi- 

 croscopic living bodies ; when our bodies increase, he held it 

 was owing to an addition of animalcula ; when they diminish, 

 to a subtraction of these creatures. Another very common' 

 opinion was to attribute independent life to the globules of 

 the blood ; nay, in a manual of zoology published in the year 

 1829 by Reich enbach, these important particles are repre- 

 sented along with the Spermatozoa, as the first family of the 

 animal kingdom. 



The doctrine of the spontaneous origin of the infusoria ob- 

 tained considerable amplification upon the publication of thein- 

 vestigations of several inquirers (Fray, Gruithusen), ix). which it 

 was pretended that infusoria were produced by the infusion of in- 

 organic substances in distilled water, artificial gases alone being 

 admitted. Professor Burdach at Konigsberg (Physiol., vol. i.) 

 also arrived at the same result ; finding, that, when freshly- 

 hewn granite was exposed, with distilled water and oxygen or 

 hydrogen, to the solar light, there appeared a green matter, 

 with threads of Confervse. This learned professor believes 

 that the presence of the four elements of the ancients is the 

 only condition required for the production of life in its lower 

 forms. 



Sect. 2. The Theory of Equivocal Generation was applied to 

 Intestinal Worms. — If equivocal generation were to be adopted 

 at all, it would very naturally be applied to intestinal worms. 

 The profound researches, of Goeze, Zeder, Rudolphi, and 

 Bremser, on the subject of these animals, at the close of the 

 18th and beginning of the 19th century, only more firmly 

 persuaded them that a spontaneous origin was not only ad- 

 missible, but was the common mode of production in this 

 group. What had hitherto induced the belief that intesti- 

 nal worms were introduced into the body from without, was 

 the (pinion that these worms were identical with common 



VOL. XXXI. NO. LXII,— OCTOBER 1841. X 



