324 



The Origin of Infusoria. 



fusoria might have appeared in the smaller vessel, as they can 

 certainly be obtained with very small quantities of fermenting 

 hay;* but if not, it does not follow, as these gentlemen consider, 

 that the existence of germs in the atmosphere is disproved, as 

 the small quantity of filtered infusion may not have contained 

 enough of some particular substance to facilitate the develop- 

 ment of any germs which might have fallen into it. 



It is evident that controversies of this kind tend to clear up 

 obscure points in the history of infusoria, and it is a pity that 

 in England, as on the Continent, they cannot be regarded 

 from a purely scientific point of view. It is not honest to take 

 no account of facts that contradict our own notions, to cite 

 Pasteur, and omit Pouchet or Wyman. As the matter really 

 stands, there are discrepancies which have to be explained, and 

 the vast assemblage of objects grouped together as " infusoria" 

 differ so widely in structure as to countenance the idea that 

 their mode of origin may not be the same. We may mention 

 that the French Academy has appointed a Commission, com- 

 posed] of M.M. Milne-Edwards, Flourens, Brongniart, and 

 Coste, to report upon the papers on Spontaneous Generation 

 sent in to compete for the Alhumbert prize. 



The Eggs op Infusoria (Balbiani). 



Diameter of Eggs 

 in fractions of a 



Name of Species. 



Trachelius ovum 

 Amphileptus gigas (?) 



„ anas . 



Loxophyllum meleagris 

 Loxodes rostrum . 

 Chilodon cucullus . 

 Bursaria truncatella . 

 Ophryoglena flava 

 Spirostomum teres 



„ ambiguum 



Stentor casruleus . 

 Euplotes patella . 

 Stylonichia mytilus 



„ pustulata 



Urostyla (undetermined) 

 Paramecium aurelia . 

 bursaria 



Number of 

 Eggs. 



2 

 20—25 



2 

 12—15 

 15—20 



1 0-005 



4 



4 



2—3 



20—50 



8—15 



2 



4 



4 



100 or more 



4 



2—4 



(undetermined) 20 — 25 



Millemetre.f 



0-120 

 0-018 

 0-008 

 0-015 

 0-015 

 —0-020 

 0-057 

 0-018 

 0-018 

 0-014 

 0-021 

 0-014 

 0-018 

 0-010 

 0-007 

 0-018 

 0-014 

 0-007 



* Mr. Slack tells us that lie has obtained kolpods and other ciliated infusoria 

 in vessels containing half a grain of chopped hay and two drachms of distilled 

 water. 



t The millemetre is equal to 0*0394 of an inch. 



