312 Transactions of the Society. 



appears suspended. These big vacuoles may be looked at for hours- 

 without their disappearing, but they are seen to get slowly bigger^ 

 or to coalesce with others. Some of my observations seem to prove 

 that their functions might be those of a contractile vesicle, for on 

 three different occasions I have seen them bursting, and the 

 wounded place immediately'' closing. 



Transformation into a Swimming- State. 



In introducing the subject concerning division in Follicidinaj 

 Sahrlage devotes a few pages to the discussion of some phenomena 

 which have been mentioned, or rather guessed at, by several 

 observers, and which would presuppose a voluntary abandonment 

 of the shell ; and it seems worth while to reproduce here the lines 

 of the German author : — 



"Wright claims to have observed the multiplication of his 

 Lagotia producia by means of ciliate vermiform larvae, which were 

 swimming about, continually revolving on their long axis, but nO' 

 clue could in fact be obtained about the origin of these larvse. He 

 describes how these vermiform larvae stretch, become pointed behind, 

 flatten anteriorly, and during the night (!), swimming at the surface 

 of the water (?), secrete an envelope, and in three to four days also 

 form the lobes of the peristome. All these statements are more than 

 doubtful, the more so that the Ensjlish investigation of Infusoria 

 was at that time largely ' dilettantisch,' and rather considered as a 

 scientific sport. Stein already doubts the statements of Wright,, 

 tries to explain them by careless observations, and supposes that 

 the ' larva3 ' were ordinary individuals in a young state, which had 

 left their shells (?), or old animals which had been detached from 

 their envelope on the bottom of the aquarium. When Stein further 

 adds that he had not infrequently seen, in the water of his vessels 

 in which were kept weeds with envelopes of FoUiculina, specimens 

 which were swimming about and had left their shells, I must on 

 the ground of my experiences consider the statement as rather 

 doubtful. ..." 



" Claparede and Lachmann claim also to have observed Freia 

 elcgans in its swimming young form. It resembles Wright's larvse, 

 is able to contract into a sphere, swims ' avec grande vivacite,' and 

 is about 85 /i in length. No mouth could be observed, but a black 

 ocular spot (!) at the anterior part of the body ; the nucleus was 

 oval in shape. Lachmann was in one (!) case witness of a fixation 

 on alga3, after which the pigment-spot dissolved, and at the anterior 

 end a membranous extension appeared, which I should be disposed 

 to consider as moribund phenomena. Claparede and Lachmann 

 supposed also a subsequent formation of a shell, but unluckily the 

 specimen concerned was lost sight of! At the same time, and 



