Of, 





-cted 

 to 



k^i 



\ 



exp 



I 





^I^^^ble, undent 

 ^ng into a 



1 



And si 



similarl' 



'ads, Actino 



ns frequently pij 



cover 



to a ?fl)' 



► 



iny of the % 

 nd probably era 



■ed from differ: 



» 



^r 



1 



and that d 



a 



fusoria niaj^"'\ 

 vcsicks or 



otic 



:t 



CO 



that ev 



nvertibil^'' 



ured to 3^;:,1 



he P 



(pp. n 







7y/£ BEGINNINGS OF LIFE 



493 



ions 



And, as a matter of fact, phenomena of this kind 

 have been long ago and quite independently recorded 

 by different investigators. Hitherto such observa " 

 have been almost v/holly discredited — not because there 

 was any reason to suppose that due care had not been 

 exercised by those who made them, but simply because 

 the facts recorded were not in harmony with the theo- 

 retical views held by the majority of biologists. This 

 rejection of facts which do not accord with generally 

 received theories is unfortunately only too common. 



Two sets of observations which were made many 



:he same mattj years ago, and quite independently of one another, are 



to a certain extent complementary. The metamor- 

 h one anotkiif P^^o^^s of Vorticella into Oxytricha was described by 



M 



^SS 



M.Jules 



M 



observations^ were made upon speci- 

 ' Tnt rauto^f "^^"^ ^^ Vorticellge which had been developed in great 



napellus. Some of 



Aconltum 



them were seen to undergo longitudinal fission and 

 produce buds in the usual manner, though others after 

 a time passed into the encysted condition. The body 

 contracted, assumed a spherical form, and produced a 

 secretion which soon solidified into a tolerably thick 

 cyst-wall, whilst the pedicle shrivelled and gradually 

 disappeared (Fig. 90, a^ h) 2. These encysted Vorticellse 



'^ 'Ann. des Sc. Nat.' 1848 (Zool.), p. 99. 



"' On other occasions a posterior ciliary wreath is developed, and the 

 organism separates from its pedicle before it begins to encyst itself. 



