THE BEGINNINGS OF IIFE. 509 



small Rotifers, even the largest forms — such as Brachion 

 and Hydatina — have frequently been seen to arise from 

 the transformation of large specimens of Euglen^e, both 

 rose-coloured and green. Some of these when con- 

 tracted formed spheres as much as ^|^" in diameter, 

 and the transformation took place either with or without 

 the previous formation of an enveloping cyst — though 

 generally under the former conditions ^ The real 

 nature of the cyst was, moreover, in certain cases quite 

 obvious, even at a late stage, owing to its containing 

 an unmetamorphosed portion of the original Euglena 

 substance, in contact with the embryo Rotifer. 



The next reference to the heterogenetic origin of 

 Rotifers occurs in the writings of M. Nicolet, to which 

 we have already referred 2. He says that such organisms 

 are often met with amongst the multitudinous forms 

 of Infusoria which he has seen budded off from the 

 closed internodes of Chara ; and he figures the kind 



on examining the green and foul-looking drainage from the manure-heap 

 in the farm-yard. Amidst its swarms of Euglense we have usually found 

 a rich supply of Rotatoria.' 



^ Speaking of such transformations which were seen in Germany 

 during the year 1852, and in the month of August, Dr. Gros says : — * En 

 general, a cette epoque d'observation, se produisaient surtout les grandes 

 espbces de Systolides, ceux derives des Euglenes entieres transformees, 

 depuis les Hydatines jusqu'aux plus grand Brachions. Dans quelques- 

 uns de ces individus nees sans parents, on percevait deja les oeufs de leur 

 future lignee, et ces caufs, soil dans le corps maternel, soil pondtis, ne pou- 

 vaient etre confundus avec ceux resultant des transformations EugUniennes, 

 qui ont d'ailleurs ete suivees non sur quelques individus, mais on pent dire sur 

 des millions.' (See also loc. cit, pp. s^i, 324, 325, and 333 ; PI. C, figs. 

 8 and 13.) ^ See p. 47S. 



