90 ORGANIZATION OF THE INFUSORIA. 



The investigator, to whom credit is due for first demonstrating the 

 sporiparous mode of multiplication among the Flagellata, and for indi- 

 cating with reference to such peculiarity the close approach made by this 

 group to the Palmellaceae and other Protophytes, is without doubt Pro- 

 fessor L. Cienkowski, who in the year 1865* figured and described at 

 length such "sporular multiplication in connection with his Monas (Heter- 

 omitd) amyli, various species of his newly founded genus Pseudospora, 

 and several types of ordinary Rhizopoda. Although he discovered such 

 developmental phenomena, Cienkowski, however, scarcely attributed to 

 them the interpretation here adopted, the quiescent or encysted condition 

 and transitional amoeboid phases being treated by him as more essential 

 and characteristic than the motile flagelliform bodies issuing from the spores, 

 named by him " zoospores," and which certainly represent the typical 

 form of expression of the species in its most mature condition. Not only, 

 however, did Cienkowski recognize the respective natatory or flagel- 

 liform, amoeboid or repent, and quiescent or sporular conditions of the 

 above-named types, but he also witnessed the conjugation or coalescence in 

 several instances of two or more zooids during the amoeboid stage, and the 

 construction by them of a single sporocyst. In connection with this last- 

 named phenomenon, he sagaciously recognized the close approach made to 

 the construction of the compound plasmodium of the Myxomycetes, at 

 that time the subject of special observation by de Bary and himself, 

 and to a certain extent, also, anticipated the more prominent points in 

 the life-history of certain monadiform species revealed a few years later 

 through the painstaking investigations of our own countrymen, Messrs. 

 Dallinger and Drysdale. Full details of the somewhat varying phenomena 

 presented by the diverse types examined by these two authorities 

 being recorded in connection with the systematic descriptions of the 

 Flagellata given further on, and among which may be more especially 

 cited such forms as Monas Dallingerii, Ccrcomonas typica, and Heteromita 

 itncinata, it will suffice here to indicate that Messrs. Dallinger and Drysdale 

 established in every instance the interpolation among the ordinary mode 

 of multiplication by binary division of a spore-producing phase, accom- 

 panied by the assumption of the individual zooid of a resting or encysted 

 state. Preceding such encystment a transitory repent amoeboid condition 

 was usually exhibited, and was in most instances accompanied by the 

 coalescence of two or more such amoeboid units. In certain cases the 

 sporular bodies so produced were of such a size and number as to fall 

 under the category of macrospores, while in a few others they were of such 

 excessive minuteness and corresponding numbers as to defy individual 

 definition with the magnifying power of 15,000 diameters brought to bear 

 upon them with the aid of a ^V~ mc h objective. These three leading phases 

 in the life-history of a Monad, as above enumerated, and which may be 

 respectively denominated the active flagelliferous, the transitory amoeboid, 



* 'Arch. f. Mik. Anat.,' Bd. i. 



